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   Index



 

EUPHORBIACEAE

(Spurge family)

 

This large plant family, comprising some 5000 species in 300 genera, is of cosmopolitan distribution except for polar regions. Few species have a very wide range, the largest and most wide-ranging genus being Euphorbia L.

Several species are grown commercially. The latex of Hevea brasiliensis Müll.Arg. provides the raw material from which rubber is manufactured; the seeds of Croton tiglium L. are the source of croton oil, previously a medicinal item, but lately a source of useful pharmacologically active compounds; the seeds of Vernicia fordii Airy Shaw provide tung oil. The poinsettia (Euphorbia pulcherrima Willd.), various Acalypha L. species, and the garden croton (Codiaeum variegatum Blume var. pictum Müll.Arg.) are grown for the houseplant trade as are a number of cactiform succulent Euphorbia L. species such as Euphorbia milii Des Moul. (the crown of thorns) and Euphorbia tirucalli L. (the pencil tree).

A number of species feature in local folk medicine, many being used for their purgative properties or as topically applied wart removers (Watt & Breyer-Brandwijk 1962, Morton 1981, etc.). These activities (and also piscicidal activity) are usually associated with the presence of tigliane, ingenane, or daphnane polyol esters. Perhaps the only product currently used in Western medicine is castor oil derived from the seeds of Ricinus communis L. Its purgative action is associated with its content of ricinoleic acid glycerides (Wade 1977). The oil also finds use in the manufacture of certain cosmetics. The asthma plant (Chamaesyce hirta Millsp., syn. Euphorbia hirta L.) has found use as a herbal remedy for the treatment of asthma and coughs (Todd 1967).

Some members of this family are stinging nettles, and can cause skin irritation as a result of contact with their stinging hairs. A far greater number of species are known to possess an irritant and purgative sap, latex, or seed oil, the activity being associated with the presence of diterpenoid esters based on the tigliane, ingenane, and daphnane hydrocarbon skeletons. A few species that are often cultivated as house plants have contact allergenic properties, but the compounds responsible for this property have not been identified. The spines of many cactiform species of the genus Euphorbia L. in particular are capable of producing mechanical injury.


Acalypha L.
Copper Leaf, Three-Seeded Mercury

About 450 species are found in tropical and sub-tropical regions. Several are grown as houseplants for their decorative foliage.



Acalypha hispida Burm.f.
[syn. Acalypha densiflora Blume]
Chenille Plant, Redhot Cat-Tail, Philippine Medusa

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Acalypha indica L.
Indian Acalypha, Indian Copperleaf, Indian Nettle, Indisches Kupferblatt

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex. Smitinand & Scheible (1966) note that this species causes irritation of the skin, ascribing the action to hydrocyanic acid in the hairs of the leaves and stems. Uphof (1959) records that Acalypha indica has been used as a gastrointestinal irritant, and that large doses are emetic.



Acalypha pruriens Nees & Mart.

The specific epithet of this eastern Brazilian plant suggests that it can produce itching.



Acalypha virginica L.
Mercuryweed, Virginia Copperleaf, Virginia Three-Seeded Mercury, Waxballs, Virginischer Katzenschwanz, Virginisches Kupferblatt

Pammel (1911) lists this species as being diuretic and irritant.



Acalypha wilkesiana Müll.Arg.
Beefsteak Plant, Fire Dragon Plant, Jacob's Coat, Match-Me-If-You-Can, Buntlaubiges Kupferblatt

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex. To reduce a fever, the large leafy branches have been wrapped around the patient to induce perspiration through the rubefacient action of their leaves (Morton 1981).



Acidoton Sw.

Six species are found in the West Indies, Central America, and northern tropical South America. Stinging hairs are found in members of this genus (Thurston & Lersten 1969).



Acidoton microphyllus Urb.

This species can produce dermatitis (Pardo-Castello 1923).



Acidoton urens Sw.
[syn. Acidoton innocuus Baill.]
Mountain Cowitch, Smooth-Leaved Cowitch

Pardo-Castello (1923) notes that this species can produce dermatitis. Wimmer (1926) and von Reis Altschul (1973) refer to its stinging hairs.



Agrostistachys Dalz.

Eight or nine species are found from India and Sri Lanka to western Malaysia.

Small black ants, which habitually make their nests on the stems among the bases of the leaves, fiercely resent interference with their abodes (Corner 1952). Such plants may be described as super-nettles if the bites and/or stings of the ants elicit a pseudophytodermatitis (Schmidt 1985).



Aleurites J.R.Forst. & G.Forst.

The genus comprises just two species (Stuppy et al. 1999), other taxa previously regarded as Aleurites species having been moved to the genera Reutealis Airy Shaw (1 species) and Vernicia Lour. (3 species).



Aleurites moluccanus (L.) Willd.
[syns Aleurites trilobus J.R.Forst. & G.Forst., Jatropha moluccana L., Mallotus moluccanus (L.) Müll.Arg.]
Candleberry, Candlenut Tree, Indian Walnut, Lumbang Tree, Otaheiti Walnut, Varnish Tree

The nut oil, known as candlenut oil or lumbang oil, is used as a rubefacient (Burkill 1935). Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Anthostema aubryanum Baill.

The latex from this West African species is very caustic and can cause temporary blindness (Irvine 1961).



Anthostema senegalense A.Juss.

The latex from this West African species is strongly caustic and dangerous to the eyes (Irvine 1961).



Baliospermum axillare Blume
[syns Baliospermum montanum Müll.Arg., Jatropha montana Willd.]
Jungle Jamalgota

The leaves and the oil from the seeds are irritant (Behl et al. 1966) and rubefacient (Nadkarni 1976). The poisonous seeds and their oil are drastic purgatives (Chopra & Badhwar 1940), used in India instead of the seeds and oil from Croton tiglium L. (Burkill 1935).

Ogura et al. (1978) reported the presence of montanin (a daphnane polyol ester), baliospermin, and other tigliane polyol esters in Baliospermum montanum.



Caperonia palustris (L.) A.St.-Hil.
[syns Croton palustris L., Argythamnia palustris (L.) Kuntze]

According to a note found on an herbarium specimen, this species has stinging hairs (von Reis Altschul 1973).



Chamaesyce Gray

This is a genus of some 250 species of cosmopolitan distribution, which is considered by some authorities to be a sub-genus of Euphorbia L.



Chamaesyce adenoptera Small
[syn. Euphorbia adenoptera Bertol.]
Bois de Rose, Jerba di Lechi

The caustic sap is used as a "first-aid" styptic (Morton 1981).



Chamaesyce buxifolia Small
[syns Euphorbia buxifolia Lam., Chamaesyce mesembryanthemifolia Dugand, Euphorbia mesembryanthemifolia Jacq.]
Coast Spurge

Cuban bathers treat sea urchin punctures of the foot with the latex of this species (Morton 1981).



Chamaesyce chamaesyce Hurusawa
[syns Euphorbia chamaesyce L., Tithymalus chamaesyce Moench]

Pammel (1911) lists this species as being irritant.



Chamaesyce drummondii Soják
[syn. Euphorbia drummondii Boiss.]
Caustic Weed, Milk Weed, Mat Spurge

There is conflicting data concerning the effects of this plant. Pammel (1911) lists this species as being irritant. Orchard (1954) also states that the plant is irritant to human skin, but Stanley (1896) found that the latex had no caustic or even irritant action on the eye of the sheep or dog. Apparently the fresh milky sap is considered by Australian bushmen to possess great healing qualities (Hurst 1942). She also stated that the head of a sheep that has eaten the plant swells to an enormous extent and becomes so heavy that the animal cannot support it. It has also been noted that eating the flesh of pigeons that have fed on the fruit of the plant causes sickness in man (Cleland 1914).



Chamaesyce glomerifera Millsp.
[syn. Euphorbia glomerifera Wheeler]

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap or latex.



Chamaesyce hirta Millsp.
[syns Euphorbia hirta L., Euphorbia pilulifera auct. non L., Euphorbia capitata Lam.]
Asthma Plant, Asthma Weed, Hairy Spurge, Pill-Bearing Spurge

The common name asthma plant is derived from the use of extracts of the herb for the relief of asthma (Wren 1975).

The sap has been described as irritant by various authors: Chopra & Badhwar (1940); Watt & Breyer-Brandwijk (1962); Souder (1963); Behl et al. (1966). According to Morton (1972b), gardeners in Florida, where this species is a common lawn weed, can develop dermatitis of the hands, particularly of the sides of the fingers after pulling this weed. Uhe (1974) records that Euphorbia hirta is used in Samoa as a skin-irritant and anti-asthmatic. However, patch tests carried out using the leaves of this species crushed in a small quantity of normal saline elicited positive reactions in only 2 of 18 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978). From his personal experience, Arnold (1968) in Hawaii states that the sap is not particularly irritating to the skin. Further, it is difficult to reconcile the reported skin irritant effects with the oral use of extracts of the herb evidently without concomitant purgation. It is likely that any dermatitic effects appropriately ascribed to this species have been of allergic rather than irritant aetiology.



Chamaesyce hypericifolia Millsp.
[syns Euphorbia hypericifolia L., Euphorbia lasiocarpa Klotzsch]

The juice is used as a caustic on skin lesions (Watt & Breyer-Brandwijk 1962). Chopra & Badhwar (1940) also note that the plant contains an acrid and vesicant juice.



Chamaesyce hyssopifolia Small
[syns Euphorbia hyssopifolia L., Euphorbia brasiliensis Lam.]
Wart Weed, Chicken-Weed Hembra

The caustic sap is applied to warts, callouses and ringworm, and in Brazil, on cataracts and chronic ulcers (Morton 1981).



Chamaesyce maculata Small
[syns Euphorbia maculata L., Tithymalus maculatus Moench]
Spotted Spurge, Eyebane

This native plant of the eastern and mid-western United States occurs as an occasional weed in the Pacific states. It has irritant latex (Hardin & Arena 1974).



Chamaesyce nutans Small
[syns Euphorbia nutans Lagasca, Euphorbia preslii Guss., Chamaesyce preslii Arthur]
Pasture Spurge, Spotted Spurge, Eye-Bright

Application of the juice to the eyes causes severe irritation with smarting, burning, lachrymation, and momentary blindness (Pammel 1911).



Chamaesyce pilulifera Small
[syn. Euphorbia pilulifera L.]

Pammel (1911) notes that this species produces dermatitis.



Chamaesyce prostrata Small
[syn. Euphorbia prostrata Aiton]
Prostrate Spurge

The plant occurs as a weed in the Sydney district of Australia, and is common in townships in Queensland (Blakely 1923).

The milky sap is sometimes applied to sores on the skin and is not known to be irritant (White 1927). Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap or latex. Martinez (1969) noted a report of an irritant action in a Materia Medica and applied the juice to the eyes of animals but did not see the irritant action that he expected.



Chamaesyce thymifolia Millsp.
[syn. Euphorbia thymifolia L.]
Chicken-Weed, Eyebright, Wart Weed, Thyme-Leaved Spurge

The latex can cause dermatitis (Pammel 1911, Souder 1963), and is vesicant to the skin of many individuals (Allen 1943). Chopra & Badhwar (1940) also note that this species contains and acrid and vesicant juice.



Chiropetalum griseum Griseb.
[syn. Argithamnia mollis Kuntze]

The plant has irritant effects on contact with the skin (von Reis Altschul 1973).



Claoxylon carolinianum Pax & K.Hoffm.

The latex sometimes poisons the skin (von Reis & Lipp 1982).



Claoxylon marianum Müll.Arg.
Panao, Cator

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Clutia pulchella L.

The juice of this plant produces irritant effects (Watt & Breyer-Brandwijk 1962).



Cnesmone Blume
[syn. Cenesmon Gagnepain]

Ten species are found in Assam, southern China, south-eastern Asia, and western Malaysia.

Stinging hairs are known in members of this genus (Wimmer 1926, Thurston & Lersten 1969).



Cnesmone javanica Blume
Jelatang Rusa

This species, a slender climber with stinging hairs (Burkill 1935), is strongly hirsute and urticating (Airy Shaw 1975). Smitinand & Scheible (1966) record that all parts of the plant are covered with stinging hairs which cause irritation and pain when they touch the skin. Ridley (1898) and Gimlette (1929) agree that the plant does not sting severely.



Cnesmone laevis Airy Shaw
[syn. Tragia laevis Ridl.]

This climbing plant of Malaya possesses stinging hairs and is known to produce skin reactions (Airy Shaw 1969, Kochummen 1972). Ridley (1923) and Burkill (1935) noted that the plant does not sting badly.



Cnesmone laotica Croizat
[syn. Cenesmon laoticum Gagnepain]

This is an undershrub with stinging hairs (Airy Shaw 1969).



Cnesmone subpeltata Ridl.

This climbing plants possesses irritant hairs and is known to produce skin reactions in Malaya (Kochummen 1972).



Cnidoscolus Pohl
Spurge Nettle

This tropical American genus comprises some 75 species of nettles. Cnidoscolus was at one time included within Jatropha L. from which it was separated on the basis of its stinging hairs (Thurston & Lersten 1969).

Stinging hairs have been noted on the following species (von Reis Altschul 1973, Jacobsen 1974, Bailey & Bailey 1976, Morton 1981):

Cnidoscolus angustidens Torr.
[syn. Jatropha angustidens Müll.Arg.]
Cnidoscolus chayamansana McVaugh
Cnidoscolus cnicodendron Griseb.
Cnidoscolus multilobus I.M.Johnst.
[syn. Jatropha multiloba Pax]
Cnidoscolus texanus Small
[syn. Jatropha texana Müll.Arg.]
Cnidoscolus tubulosus I.M.Johnst.
[syn. Jatropha tubulosa Müll.Arg.] 


Cnidoscolus longipes (Pax) I.M.Johnst.

This species has caustic latex (von Reis Altschul 1973).



Cnidoscolus stimulosus (Michx.) Engelm. & A.Gray
[syns Cnidoscolus urens var. stimulosus (Michx.) Govaerts, Jatropha stimulosa Michx., Jatropha urens var. stimulosa (Michx.) Müll.Arg.]
Tread-Softly, Bull-Nettle, Spurge Nettle, Stinging Spurge

This species, found in dry sandy woods, fields, and sandhills from Florida to Texas and north to Virginia, has stinging bristles (Fernald 1950, Thurston & Lersten 1969). Wimmer (1926) referred to the stinging hairs of "Jatropha stimulata". Hardin & Arena (1974) noted that urticaria can arise from contact with the plant; von Reis Altschul (1973) similarly noted that red welts are produced by the painfully stinging hairs on contact.



Cnidoscolus urens (L.) Arthur
[syn. Jatropha urens L.]
Brazilian Stinging Nut

The latex is capable of burning the skin to produce serious sores; the poisonous hairs produce great irritation of the skin which may last for several days (Watt & Breyer-Brandwijk 1962, von Reis & Lipp 1982). Dahlgren & Standley (1944), describing edible and poisonous plants found in the Caribbean region, cautioned that Jatropha urens is thickly covered with stiff hairs which sting severely and cause pain and inflammation, often with numbness lasting a day or more. Wimmer (1926) referring to Jatropha urens, Standley (1927), Standley (1937b), Dao (1967) referring to Jatropha urens, and von Reis Altschul (1973) also refer to the stinging hairs of this species. Lutz (1914) described an extreme reaction following contact with 10 of the stinging hairs on the left hand. This resulted in an increasingly painful swelling of the hand spreading to the arm and subsequently to the other arm and to the face about the eyes and nose. A strong itching sensation was felt over the upper parts of the body; red pimples appeared everywhere. Cardiac and respiratory distress led to unconciousness.

This species is considered to be dangerous to both man and livestock (Lutz 1914).



Cnidoscolus vitifolius Pohl
[syn. Jatropha vitifolia Mill.]

von Reis Altschul (1973) records that this species has poisonous juice and stinging hairs.



Codiaeum A.Juss.

Fifteen species are found in Malaysia, Polynesia, and northern Australia.

The "crotons" commonly grown as house plants are cultivars of Codiaeum variegatum A.Juss. The other species of Codiaeum are very rarely grown.



Codiaeum variegatum A.Juss.
[syn. Codiaeum variegatum A.Juss. var. pictum Müll.Arg., Codiaeum variegatum Blume, Croton pictus Lodd., Croton variegatus L.]
Croton, Garden Croton

Notwithstanding the common name of these plants, they should not be confused with members of the genus Croton L.

Different leaf forms and colour variations often appear on the same plant as a result, it is said, of genetic instability. A colourless liquid that bleeds from the broken leaf stem stains white cloth to a brown colour which increases in darkness when the fabric is wetted. These markings have been mistaken for blood stains (Brown 1960a).

The young leaves of certain of the yellow varieties are eaten as flavouring; old leaves irritate the mouth because their acridity increases with age (Brown 1960a). The bark and roots are acrid and cause burning in the mouth if chewed. Although mature leaves may be irritant, the plant is rarely a cause of dermatitis despite much handling of foliage for decoration and of cuttings for propagation (Morton 1962a). Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex; Allen (1943) stated that handling of, or even proximity to, the plant in Panama can produce in many individuals a dermatitis resembling erysipelas.

A positive patch test reaction to the leaf has been observed in one patient by Agrup (1969). A flower grower who had hyperkeratotic eczema localised to the tips of the thumbs and index fingers showed positive patch test reactions to the leaf and stalk of the plant, negative in 5 controls. The sensitiser seemed to be soluble in water but not in alcohol (Tafelkruyer & van Ketel 1976). Hausen & Schulz (1977b), Schmidt & Ølholm Larsen (1977), and van Ketel (1979a) also reported allergic contact dermatitis to the plant in gardeners. Both Hausen & Schulz (1977b) and van Ketel (1979a) reported that guinea pigs could be sensitised to a methanolic extract of the plant, and that the plant was not an irritant. Soejarto et al. (1977) were of the opinion that the Codiaeum of Schmidt & Ølholm Larsen (1977) was in fact a Croton L. species, but this was subsequently refuted (Schmidt & Ølholm Larsen 1978).



Colliguaja odorifera Molina

This species is said to be irritant (Schwartz et al. 1957).



Croton L.

About 750 species are found in tropical and sub-tropical regions. Crotons of horticulture belong to the genus Codiaeum A.Juss.

Croton cascarilla Bennett and Croton eluteria Bennett yield cascarilla bark, used as a tonic and to scent tobacco (Nicotiana tabacum L., fam. Solanaceae). Croton lacciferus L. yields a lac used in varnish making.



Croton astroites Dryander
Maran, Black Balsam, Wild Marrow

The plant possesses toxic properties similar to those of Croton tiglium L. (Oakes & Butcher 1962). They stated that croton oils are concentrated in the seeds but also occur in the stems and leaves.



Croton capitatus Michx.
Hogwort

The plant can produce dermatitis (Shelmire 1940) and is described as an infrequent sensitiser. An extract of the plant produced a positive patch test reaction in 1 of 50 patients who had "weed dermatitis" (Shelmire 1939a).



Croton ciliato-glanduliferus Ortega
Ciega-Vista

The plant is said to irritate the eyes, causing inflammation and blindness (von Reis Altschul 1973). The sticky hairs that clings to the hands after touching the plant causes severe inflammation on contact with the eyes (Dahlgren & Standley 1944, Morton 1981).

Cattle are said to have been blinded as a result of grazing among these bushes (Dahlgren & Standley 1944).



Croton cortesianus Kunth
[syn. Croton trichocarpus Torr.]
Pozual

The juice is used as a caustic for the treatment of skin diseases (Uphof 1959, Martinez 1969).



Croton elliotianus Baill.

The seed is a drastic purgative in man; the seed oil does not have vesicant properties but is purgative though less so than the seed (Watt & Breyer-Brandwijk 1962).



Croton eluteria Bennett
Cascarilla, Sweetwood Bark

A fragrance raw material, cascarilla oil, is prepared from the steam distillate of the bark of this species (Arctander 1960). No irritant, sensitising, nor phototoxic effects could be demonstrated with the undiluted oil in various test animals including man (Opdyke 1976, p. 707).



Croton flavens L.
[syn. Croton rhamnifolius Standl.]
Rock Balsam, Yellow Balsam

The plant is extensively used for medicinal and food purposes in Central America and the West Indies (Morton 1981).

Highly skin irritant and cocarcinogenic 16-hydroxyphorbol and 4-deoxy-16-hydroxyphorbol esters have been isolated from this species (Weber & Hecker 1978).



Croton gratissimus Burchell

The plant is used by the Zulu as a cathartic and as an eruptive irritant. The bark is applied for its irritant action on the chest wall in any painful respiratory condition and in intercostal neuralgia (Watt & Breyer-Brandwijk 1962).



Croton gubouga S.Moore

A burning sensation in the mouth is produced by chewing the seeds (Watt & Breyer-Brandwijk 1962).



Croton hentyi Airy Shaw
[syn. Croton hirtus L'Hér.]

Hairs on the stem are said to be "stinging", but perhaps irritant rather that urticating (Airy Shaw 1980).



Croton humilis L.
Ikaban, Pepper-Bush, Pepper Rod, Small Seaside Balsam

In Yucatan, the sap of this species is said to cause blindness in cattle (Morton 1981).



Croton impressus Urb.
Palo de Verraco

This species is among the 14 commoner causes of plant contact dermatitis in the Dominican Republic (Brache & Aquino 1978).



Croton megalocarpus Hutch.
[syn. Croton elliottianus Engl. & Pax ex Pax]
Musine

The wood has been used for flooring in England. The fresh wood has an objectionable smell, and the sawdust irritates the nose and throat of some workmen (Anon 1957).



Croton monanthogynus Michx.
Prairie Tea

Shelmire (1940) observed that an extract of the plant produced negative patch test reactions in 50 patients who had "weed dermatitis", and stated that the plant was an infrequent sensitiser.



Croton mubango Müll.Arg.

Watt & Breyer-Brandwijk (1962) record that this species is a drastic purgative.



Croton niveus Jacq.
Cascarilla

The leaf juice is applied on dermatitis caused by Hippomane mancinella L. (Morton 1981).



Croton origanifolius Lam.
Tremolina

This species is one of the 14 commoner causes of plant contact dermatitis in the Dominican Republic (Brache & Aquino 1978).



Croton roxburghii Balakr.
[syn. Croton oblongifolius Roxb.]

The seed oil is a drastic purgative (Chopra & Badhwar 1940).



Croton sparsiflorus Morong

Phorbol esters have been isolated from the seeds of this species (Upadhyay & Hecker 1976).



Croton sylvaticus Hochst.

A burning sensation in the mouth and throat is produced by chewing the seeds (Watt & Breyer-Brandwijk 1962).



Croton texensis Müll.Arg.
Texas Croton

Pammel (1911) notes that this species sometimes causes irritation of the skin.



Croton tiglium L.
Purging Croton, Chenkian, Chemekian

The seeds are the source of croton oil (Oleum Tiglii), the vesicant nature of which is well recognised (Uphof 1959, Smitinand & Scheible 1966, Nadkarni 1976). The oil has been rubbed on the scalp as an irritant "hair-producing" application (White 1887). Its use as a counter irritant by application and by pricking into the skin for pulmonary disease, a process called "Baunscheitismus", fell into disuse (White 1887). Taken orally, it is a drastic purgative; its use in human and veterinary medicine has been largely abandoned because of its toxicity and violent action.

The bark exudes a kino (astringent tannin). The smoke from the burning wood irritates the eyes (Burkill 1935). Croton oil has been used for illumination, but only outdoors since the fumes of the burning oil are irritant to the eyes, and intolerable (Burkill 1935). The seeds have been employed for self-mutilation by malingerers (Duke-Elder & MacFaul 1972b). The oil blisters the mucous membrane of the mouth; absorption of the irritant principle through the skin can produce a purgative action. The plant seems to vary in toxicity from region to region. The oil becomes less irritating with ageing by the action of a ferment within the seeds (Burkill 1935). Croton oil may be detected in vomit by exhaustive extraction with acidulated ether, and then recognising it by its vesicating action on the skin (Gimlette 1929).

Harrison (1906) included croton oil in a list of drugs, applied externally or taken internally, which may cause dermatitis. Depending on the amount applied and the duration of application, croton oil produces an erythematous or vesico-papular reaction when applied to the skin (White 1887); folliculitis may also occur (De Carvalho 1956). The action of croton oil was compared with that of some other irritants by Björnberg (1968); 0.2% croton oil in vaseline was found to produce erythema. In contact with the eye, croton oil causes severe keratoconjunctivitis with pain, swelling, and purulent discharge (Grant 1974).

Swingle et al. (1981) compared the irritant effects of croton oil and cantharidin on mouse ears. Topically applied triamcinolone acetonide effectively inhibited the inflammation produced by the croton oil. Topically applied isoproterenol sulfate (in a pyridine/ether/water solution) also produced marked inhibition of the inflammation, whilst indomethacin (applied in acetone solution) produced some inhibition of inflammation and was the most effective of the non-steroidal anti-inflammatory compounds tested. The inflammation and epidermal hyperproliferation caused by TPA (see below) may be inhibited in guinea pigs by indomethacin (Bourin et al. 1982).

A detailed histopathological study of the effects of croton oil on the skin was made by Bandmann (1960). Electron microscopic studies of croton oil dermatitis were made by Metz (1972). Early changes in the epidermis following application of croton oil were described by Takigawa et al. (1978). Techniques for testing irritant effects of croton oil in man, using a Duhring chamber, were described by Frosch & Kligman (1979). A procedure for the comparative irritancy testing of purified croton oil constituents and related "euphorbia irritants" utilising mouse ears has been described by Evans & Schmidt (1979a).

The phorbol-12,13-diesters in the seed oil are responsible for its irritant and purgative activity. Most of these esters are also potent cocarcinogens when applied to mouse skin (Hecker 1968, Hecker & Schmidt 1974). Irritant contact dermatitis in humans from esters of phorbol and related diterpene polyols was reported by Hickey et al. (1981).

The biochemical research tool known as TPA, PMA, or compound A1 is 12-O-tetradecanoylphorbol-13-acetate. It is derived commercially from croton oil. TPA is used in the study of co-carcinogenicity or tumour promotion, and a variety of other phenomena such as the production of inflammation and platelet aggregation (Evans & Soper 1978, Evans & Taylor 1983).



Cunuria spruceana Baill.

Gunasekera et al. (1979) isolated montanin, a daphnane polyol orthoester, from this species.



Dalechampia L.

About 100 species are found in warm regions, especially in America.

Stiff, stinging hairs have been noted on the following species (Allen 1943, von Reis Altschul 1973, von Reis & Lipp 1982):

Dalechampia dioscoreaefolia Poeppig & Endl.
Dalechampia ipomoeaefolia Benth.
Dalechampia panamensis Pax & K.Hoffm.
Dalechampia tiliaefolia Lam. 


Dalechampia roezliana Müll.Arg.

Rao & Sundararaj (1951) and Thurston & Lersten (1969) refer to the early literature on the stinging hairs of this species.



Dalechampia scandens L.

The stinging hairs cause acute skin irritation (Standley 1930). Costa Ricans rub the leaves on the cheek or jaw as a counter-irritant in case of toothache (Standley 1923). Brache & Aquino (1978) note that this species is among the 14 commoner causes of plant contact dermatitis in the Dominican Republic.



Drypetes caustica Airy Shaw
[syn. Guya caustica Frappier]

This species releases mustard oil when crushed (Airy Shaw 1972); the specific epithet apparently refers to the irritant properties of the mustard oil.



Drypetes gossweileri S.Moore

von Reis & Lipp (1982) record that the slash smells of horseradish (Armoracia rusticana G.Gaertn., B.Mey. & Scherb., fam. Cruciferae).



Drypetes myrmecophila Merrill

The specific epithet suggests that this species is myrmecophilous.



Drypetes pendula Ridl.
Sabre Leaf, Gelugor Salak

Ants eat out the pith and live in the leaf twigs (Corner 1952).



Drypetes roxburghii Hurusawa
[syn. Putranjiva roxburghii Wall.]

The seeds contain glucoputranjivin and glucocochlearin, thioglucosides from which irritant mustard oils are derived when the plant material is crushed (Puntambekar 1950, Kjær 1960). See also Cruciferae.



Endospermum medullosum L.S.Sm.

According to Conn & Damas (2005b), in their online Guide to Trees of Papua New Guinea, this species bears stinging hairs.



Endospermum moluccanum Becc.
[syn. Endospermum formicarum Becc.]
Moon Tree

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap or latex. According to Burkill (1935), the plant has purgative properties.

This species has branches that are normally hollow towards their extremities, and which are inhabited by ants (Bequaert 1922).



Endospermum myrmecophilum L.S. Smith

The specific epithet suggests that the plant is myrmecophilous. Airy Shaw (1980) notes that the species has a tendency to have hollow branches but that this feature is inconstant.



Euphorbia L.
Spurge

This is the largest genus in the family comprising some 2000 species of cosmopolitan distribution. They occur chiefly in sub-tropical and warm temperate regions.

A number of species resemble cacti (fam. Cactaceae) in many respects, being armed with spines and having a xerophytic succulent form. These species in particular are popularly grown alongside cacti in collections of succulents. They are readily distinguished from cacti, however, by their milky latex which is often, but not invariably, irritant and caustic. As with cacti, mechanical injury may be sustained from their spines (Oakes & Butcher 1962). (See also Cactaceae and Didiereaceae). Botanical descriptions of the succulent species of Euphorbia are provided by Jacobsen (1974).

Theophrastus in the 4th Century B.C. noted that the juice of the spurge could cause blindness in animals and man. Culpeper (1653) wrote of the irritant effects of spurges which "abound with a hot and acrid juice, which when applied outwardly, eats away warts and other excresences"; Loudon et al. (1855) similarly noted that "The juice of every species of Spurge is so acrid that it corrodes and inflames the body wherever it is applied … externally it is dropped on warts and corns to remove them". The strongly rubefacient, depilatory, wart and freckle-removing actions of spurges were also documented by Van Hasselt & Henkel (1882). In the more recent literature, Behl et al. (1966) noted that the milky latex of many species is powerfully irritant to the skin and eye and may used by Indian villagers as a rubefacient and to remove warts. The irritant action of euphorbias in general has also been reported by Lewis (1922), Touton (1932), Roig y Mesa (1945), Williams (1949), Heyne (1950), Lipparoni (1951), Brown (1954), Watt & Breyer-Brandwijk (1962), North (1967), and several other authors.

Some 50 species of Euphorbia were listed by Pammel (1911) as being irritant.

Noors honey, which produces a hot, burning sensation in the mouth and throat (which is increased rather than decreased by drinking water), is honey prepared from the nectar of certain Euphorbia species, including Euphorbia ingens E.Mey., Euphorbia ledienii A.Berger, Euphorbia triangularis Desf., Euphorbia virosa Willd., and possibly Euphorbia cooperi N.E.Br. (Watt & Breyer-Brandwijk 1962). Upadhyay et al. (1980b) found esters of ingenol in honey derived from the nectar of Euphorbia seguieriana Necker. Morton (1964) also discussed this topic.

Euphorbia juice has been used in Africa as an ingredient of arrow poison (Dalziel 1937, Uphof 1959, Watt & Breyer-Brandwijk 1962).



Euphorbia abyssinica J.Gmelin

In Central Africa, the plant has been used as a caustic on skin lesions (Watt & Breyer-Brandwijk 1962).



Euphorbia acaulis Roxb.
[syn. Euphorbia fusiformis Buch.-Ham.]

The plant is irritant (Chopra & Badhwar 1940, Behl et al. 1966), and the latex has been used for its mild irritant effect in the treatment of chronic eczema (Agrawal et al. 1971).



Euphorbia aleppica L.
[syn. Tithymalus aleppicus Klotzsch & Garcke]

Pammel (1911) lists this species as being irritant.



Euphorbia alsinaeflora Baill.

Pammel (1911) lists this species as being irritant.



Euphorbia amygdaloides L.
[syns Euphorbia sylvatica L., Tithymalus amygdaloides Hill]

Pammel (1911) lists this species as being irritant. Gillot (1927a) notes that the seed oil is purgative and devoid of rubefacient properties.



Euphorbia androsaemifolia Willd.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex on mouse ears.



Euphorbia antiquorum L.
[syn. Tithymalus antiquorum Moench]
Malayan Spurge Tree, Sudu Sudu, Sesudu

In Malaya, this species forms a spiny cactus-like shrub or tree up to 4.5 metres in height (Corner 1952). The plant may be confused with Euphorbia lactea Haw. (Bailey & Bailey 1976).

The latex is irritant to the skin (Pammel 1911, Burkill 1935, Chopra & Badhwar 1940, Behl et al. 1966, Nadkarni 1976). Kinghorn & Evans (1975a) demonstrated the irritancy of the latex on mouse ears.

The sap is irritating to the human eye (Santos Fernandez 1892, Lampe & Fagerström 1968, Grant 1974). Blindness may occur following eye contact (Souder 1963).



Euphorbia antisyphilitica Zucc.
[syn. Euphorbia cerifera Alcocer]
Candelilla

This species, the source of candelilla wax, is irritant (Schwartz et al. 1957).

A proteolytic enzyme named euphorbain has been reported from Euphorbia cerifera (Casteñeda et al. 1943b).



Euphorbia balsamifera Aiton
[syn. Tithymalus balsamiferus Haw.]
Balsam Spurge

Dalziel (1937) recorded that the latex appears to be harmless as pieces of the young shoots are commonly sucked. He also noted that the latex was applied to treat a skin affection known as taya-ni-goyo, a Hausa term meaning "help me carry the child", on the back of a woman caused by carrying a child. Other uses indicating that the latex is not injurious to the skin were also described. By contrast, Aubréville (1936, 1950) noted that the latex is corrosive whilst Strobel et al. (1978) reported a case of bullous dermatitis of the hands in a 26 year old female who had intended to apply the latex to her face but was dissuaded from doing so after experiencing an immediate smarting pain on her hands.

Kinghorn & Evans (1975a) demonstrated very weak irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of 12-deoxyphorbol esters in the plant (Evans & Kinghorn 1977, Evans & Taylor 1983).



Euphorbia bicolor Engelm. & A.Gray

Pammel (1911) lists this species as being irritant.



Euphorbia bracteata Jacq.
[syns Pedilanthus bracteatus Boiss., Pedilanthus pavonis Boiss., Tithymalodes bracteatum Kuntze, Tithymalus bracteatus Haw., Ventenatia bracteata Tratt.]

Pedilanthus bracteatus is used locally as a violent purgative (von Reis Altschul 1973).



Euphorbia bupleurifolia Jacq.

The plant is a violent emetic and purgative and is stated to be as dangerous as croton oil (Croton tiglium L.) if taken in overdose (Watt & Breyer-Brandwijk 1962).



Euphorbia calyculata Kunth
[syns Euphorbiodendron calyculatum Millsp., Tithymalus calyculatus Klotzsch & Garcke]

The juice produces swelling and itching of the skin (Martinez 1969, Díaz 1976).



Euphorbia canariensis L.

The sap is irritating to the human eye (Lampe & Fagerström 1968, Grant 1974).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay; Lin & Kinghorn (1983) reported the presence of ingenol and 16-hydroxyingenol esters in the latex of this species.



Euphorbia candelabrum Trémaut ex Kotschy var. candelabrum
Candelabra Tree, Gifboom

Pammel (1911) listed Euphorbia candelabrum as being irritant. According to Thorold (1953), the latex is as irritant as that found in Synadenium grantii Hook.f. Watt & Breyer-Brandwijk (1962) made no mention of skin irritating activity. However, they did describe the latex as toxic and noted that it was used in arrow poisons, adding that the plant is used as a protective hedge around kraals. The wood has produced dermatitis in workers who used it to make caskets in Somalia (Lipparoni 1951).

The effects of the latex on the eye were discussed by Lewin & Guillery (1913). The latex is not particularly irritant to the rabbit eye (Lampe & Fagerström 1968, Grant 1974). Kinghorn & Evans (1975a) demonstrated the irritancy of the latex of Euphorbia candelabrum in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).

See also Euphorbia ingens E.Mey. ex Boiss. below.



Euphorbia caput medusae L.
Medusa's Head

The latex is said to be highly acrid and irritant (Watt & Breyer-Brandwijk 1962).



Euphorbia caracasana Boiss.

Pammel (1911) lists this species as being irritant.



Euphorbia cattimandoo Elliot ex Wight

This species was included in a list of Euphorbia L. species found in India, most of which reportedly contain an acrid and vesicant juice (Chopra & Badhwar 1940, Behl et al. 1966).



Euphorbia chamissonis Boiss.
Beach Spurge

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Euphorbia characias L. subsp. characias
[syn. Tithymalus characias Hill]

Kinghorn & Evans (1975a) demonstrated the irritancy of latex samples obtained from this taxon in a mouse ear irritancy assay.



Euphorbia characias L. subsp. wulfenii Radcl.-Sm.
[syns Euphorbia wulfenii Hoppe, Euphorbia veneta Willd.]

Pammel (1911) lists Euphorbia wulfenii as being irritant.

Kinghorn & Evans (1975a) demonstrated the irritancy of latex samples obtained from this taxon in a mouse ear irritancy assay.



Euphorbia coerulescens Haw.
Blue Euphorbia

The presence of irritant phorbol and 12-deoxyphorbol esters in this thorny succulent species was reported by Evans et al. (1975), Evans & Kinghorn (1975b), and Evans (1978).



Euphorbia collina Philippe

This species is said to be dangerous to the eyes, but this is said of all Chilean plants with milky juice (von Reis Altschul 1973).



Euphorbia cooperi N.E.Br.

This species is a tree-like succulent grown as a garden plant in Australia. It is often loosely described as a cactus even though it is spineless.

The latex is irritant to the skin and eyes and can cause blindness (Watt & Breyer-Brandwijk 1962); washing with water will not remove the irritant latex (Everist 1962). On tender skin, even a slight smear produces a blister within a short time. If a person stands within close proximity to a bleeding plant, inhalation of the air from the neighbourhood produces a burning sensation in the throat (Watt & Breyer-Brandwijk 1962).

The irritants of this species are 12-deoxy-16-hydroxyphorbol esters (Gschwendt & Hecker 1970, 1973). Kinghorn & Evans (1975a) also demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia corallioides L.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia corollata L.
Snakesmilk, Milkweed, Flowering Spurge

The juice produces vesication (Gray 1879). Coulter (1904) carried out an irritancy test on human skin with a positive result. Pammel (1911) lists this species as being irritant.



Euphorbia cotinifolia L.
[syn. Tithymalus cotinifolius Haw.]
Red Spurge, Poison Spurge, Manchineel, Manzanillo, Yerba Mala, Yerba Lechera, Barrabás

This Central American species is condemned as poisonous but is extensively planted for hedges in Guatemala City (Standley 1927). The foliage causes blisters in animals (except goats) who eat it (Blohm 1962). Morton (1962a) noted that because of its attractive dark red foliage, this shrub was introduced into the nursery trade in Florida, but some who planted it as a hedge had it removed because it was a prime contact poison. Morton (1962a) further asserted that simply touching the leaves can produce an overall rash in sensitive individuals; and that the milky sap is highly irritant and capable of producing intense inflammation and blistering on skin contact and, in the eye, at least temporary blindness. Many other authors refer to the skin irritant properties of the milky sap from this plant, including Pammel 1911, Standley 1937b, Dahlgren & Standley 1944, and Morton (1981).

Angelo Rizzo (1971) noted that the latex is not very irritating to the eyes and skin of mice, but is very irritating to the eyes and skin of man and dog.

Hirota et al. (1980) have found ingenol esters in this species.



Euphorbia cotinoides Miq.

Pammel (1911) lists this species as being irritant.



Euphorbia cyathophora Murray
Dwarf Poinsettia

This species is reportedly irritant to mucous surfaces (Everist 1972) and to the skin (Souder 1963).



Euphorbia cyparissias L.
[syn. Tithymalus cyparissias Lam.]
Cypress Spurge, Yellow Flowering Spurge

The seed oil is purgative (Gillot 1927b) and the bruised root will irritate the skin (Pammel 1911). Tithymalus cyparissias has been reported to produce a severe local reaction in the eye, characterised by iridocyclltis and hypopyon (Duke-Elder & MacFaul 1972b, Grant 1974).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay. Ott & Hecker (1981) reported the presence of 13-hydroxyingenol esters in this species.



Euphorbia deightonii Croizat

This thorny plant, which grows to 6 metres in height, has caustic latex (Dalziel 1937, Irvine 1961). Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently (Evans & Kinghorn 1977) reported the presence of ingenol esters in the plant.



Euphorbia dendroides L.
[syns Tithymalus dendroides Hill, Tithymalus arboreus Lam.]

Pammel (1911) lists this species as being irritant.



Euphorbia desmondi Keay & Milne-Redh.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1975a, 1977).



Euphorbia drupifera Thonn.
[syns Elaeophorbia drupifera Stapf, Euphorbia drupacea Stapf]

The latex, which causes considerable swelling when rubbed on the skin, is used to remove warts. It is dangerous to the eyes and can cause blindness (Oliver 1959, Irvine 1961).

The irritants of this species are ingenol esters (Kinghorn & Evans 1974, 1975a, Evans & Kinghorn 1975a).



Euphorbia dulcis L.
[syn. Tithymalus dulcis Scop.]

Upadhyay et al. (1980a) ascribed the irritancy of this species to the presence of ingenol esters.



Euphorbia epithymoides L.
[syn. Euphorbia polychroma A. Kerner]

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia eremophila A.Cunn.

Pammel (1911) lists this species as being irritant.



Euphorbia erythraea Hemsley

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia esculenta Marloth

This plant and also Euphorbia hamata Sweet are used as cattle fodder (Jacobsen 1974) suggesting that they are not strongly irritant. Watt & Breyer-Brandwijk (1962) consider that Euphorbia esculenta may nevertheless be irritant.



Euphorbia esula L.
[syn. Tithymalus esula Hill]
Wolf's Milk

This species has an irritant and acrid milky juice (Pammel 1911, Fernald 1950, Upadhyay et al. 1980a). The sap is also irritating to the human eye (Lewin & Guillery 1913, Lampe & Fagerström 1968, Duke-Elder & MacFaul 1972b, Grant 1974).

Several irritant ingenol esters have been reported from this species (Kupchan et al. 1976, Seip & Hecker 1982).



Euphorbia esula L. subsp. tommasiniana Nyman
[syns Euphorbia virgata Waldst. & Kit., Tithymalus virgatus Klotzsch & Garcke]

Upadhyay et al. (1980a, 1981) reported the presence of ingenol esters in this species.



Euphorbia exigua L.
[syn. Tithymalus exiguus (L.) Hill]
Dwarf Spurge

This species is irritant (North 1967).



Euphorbia fortissima Leach

Evans et al. (1975) and Kinghorn & Evans (1975c) reported the presence of irritant 12-deoxyphorbol esters in this species.



Euphorbia franckiana A.Berger

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex of this thorny succulent species in a mouse ear irritancy assay. The irritants appear to be esters of phorbol and 12-deoxyphorbol (Kinghorn & Evans 1975b, Evans & Kinghorn 1977).



Euphorbia fulgens Karw.

Two cases of dermatitis occurred following contact with this plant (Hausen 1974). The sap of this species has given evidence of sensitising capacity (Hausen & Schulz 1977b).

Inhalation of the pollen can cause occupational allergy (Hausen et al. 1976).



Euphorbia gaudichaudii Boiss.

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap or latex.



Euphorbia geniculata Ortega
[syn. Poinsettia geniculata Klotzsch & Garcke]

Kinghorn & Evans (1975a) found the latex to be non-irritant in a mouse ear irritancy assay.



Euphorbia genistoides Bergius

This species is irritant to the skin of sheep (Watt & Breyer-Brandwijk 1962).



Euphorbia gorgonis A.Berger

The latex is applied as an aid to the removal of warts and other skin eruptions. It is also used as a styptic (Watt & Breyer-Brandwijk 1962).



Euphorbia grandidens Haw.

The latex of this thorny succulent species is thought to be irritant and possibly capable of causing blindness (Watt & Breyer-Brandwijk 1962).



Euphorbia grandifolia Haw.
[syns Elaeophorbia grandifolia (Haw.) Croizat, Elaeophorbia leonensis (N.E.Br.) Jacobsen, Euphorbia leonensis N.E.Br.]

Referring to Euphorbia leonensis, Dalziel (1937) noted that the latex is an acrid poison causing blistering of the mouth, and that it is used by malingerers to cause sickness. Irvine (1961) referred to the caustic latex present in Euphorbia grandifolia. The irritants of this species are ingenol esters (Kinghorn & Evans 1974, Kinghorn & Evans 1975a, Evans & Kinghorn 1975a).



Euphorbia grantii Oliver
African Milk Bush

The plant is irritant to the skin and eyes (Raymond 1939) and a powerful purgative (Watt & Breyer-Brandwijk 1962).



Euphorbia hebecarpa Boiss.

Upadhyay et al. (1980a) found this species to be non-irritant in a mouse ear irritancy assay.



Euphorbia helioscopia L.
[syn. Tithymalus helioscopius Hill]
Sun Spurge, Wolf's Milk, Wartweed

Pammel (1911) listed this species as being irritant. Cleland (1931) received a report that this species caused dermatitis when handled. Varca (1937) reported two cases of a diffuse itching eruption on the face, neck and forearms after contact with the plant. Watt & Breyer-Bandwijk (1962) cite various authors who stated that the plant is irritant and vesicant to the hands and face and that severe ulceration of the skin has followed application of a poultice of the bruised plant. Some children who played with the plant in New South Wales developed blisters followed by permanent scars on their faces (Mair 1968). Formerly the juice was used for treating warts on the fingers; blistering of the lips and tongue occurred if the fingers were subsequently sucked (North 1967).

Severe kerato-conjunctivitis can result in man from exposure of the eye to this plant but, experimentally, rabbits were not susceptible (Guggenheim 1926, Lampe & Fagerström 1968, Grant 1974).

Hurst (1942) notes that Euphorbia helioscopia has been suspected as a cause of dermatitis in cows.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay; irritancy was subsequently attributed to the presence of 12-deoxyphorbol esters (Schmidt & Evans 1980).



Euphorbia heptagona L.

Pammel (1911) lists this species as being irritant.



Euphorbia heterodoxa Müll.Arg.

Pammel (1911) lists this species as being acrid.



Euphorbia heterophylla L.
[syn. Poinsettia heterophylla Klotzsch & Garcke]
Painted Leaf, Wild Poinsettia, Mexican Fire Plant, Cruel Plant

This plant, a common native weed of Florida, has an abundant milky sap which is irritant (Morton 1962a) and can produce dermatitis (Allen 1943, Orchard 1954, Pope 1968). von Reis Altschul (1973) records that in El Salvador the latex was reported to be very irritant, but in Mexico the milk of this plant is used for washing the eyes, and in Indonesia the milky sap is used instead of castor oil (Ricinus communis L.).

The latex of the plant is used as an antidote for the irritation produced by other species of Euphorbia L. (Watt & Breyer-Brandwijk 1962).

Brache & Aquino (1976) note that this spurge is among the 14 commoner causes of plant dermatitis in the Dominican Republic.



Euphorbia hoffmanniana Boiss.

This species is abundant in central Costa Rica, especially in fence rows, and is said to cause swelling and inflammation but the people seem to pay little attention to the shrub (Standley 1927).



Euphorbia hyberna L.
[syn. Tithymalus hiberna Raf.]

Pammel (1911) lists this species as being irritant. Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia ingens E.Mey. ex Boiss.
Cactus Euphorbia, Candelabra Euphorbia, Candelabra Tree, Naboom

Codd (1951) asserted that the fresh latex will blister the skin, while a drop falling in the eye will cause intense agony and temporary blindness. According to Thorold (1953), the latex is as irritant as that found in Synadenium grantii Hook.f. Watt & Breyer-Brandwijk (1962) noted that the latex produces irritation and blistering of the skin, and that it has been used as a caustic in [unspecified] skin disease. Roe & Field (1965) noted that the plant was examined as a possible source of natural rubber but it proved to be too irritant to handle on a large scale.

The latex is very irritating to the human eye, producing intense pain and temporary blindness. Cattle driven through dense bush containing the tree may suffer severe burns on the eyes, lips and facial skin … so severe sometimes as to determine the destruction of the animal (Watt & Breyer-Brandwijk 1962).

Opferkuch & Hecker (1974) identified a series of ingenol esters from Euphorbia ingens (the species from which the name ingenol is derived), and demonstrated their skin irritancy on mouse ears.

According to some authorities (Jakobsen 1974, Wickens 1976), Euphorbia ingens is a synonym of Euphorbia candelabrum Trémaut ex Kotschy var. candelabrum (see above).



Euphorbia ipecacuanhae L.
[syn. Tithymalus ipecacuanhae Klotzsch & Garcke]
Wild Ipecac

The plants are irritant to those who collect and handle them (White 1887). Pammel (1911) lists the species as being irritant.



Euphorbia jolkini Boiss.

The irritant properties of this species may be ascribed to the presence of ingenol esters (Uemura & Hirata 1973).



Euphorbia kamerunica Pax
[syn. Euphorbia barteri N.E.Br.]

The latex is caustic (Dalziel 1937). Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay. The presence of ingenol esters in this species was subsequently reported (Evans & Kinghorn 1977, Abo & Evans 1982).



Euphorbia kansui Liou

Esters of ingenol and related polyols have been reported from this species (Uemura et al. 1974, Hirata 1975).



Euphorbia kotschyana Fenzl
[syn. Tithymalus kotschyanus Klotzsch & Garcke]

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia lactea Haw.
Candelabra Cactus, Cardon, Hatrack Cactus, Dragon Bones

The plant forms a spiny shrub which is widely planted in tropical America and, as an adventive to India, is now completely naturalised and found all over that country especially near habitation. The cristate form of the plant is widely grown in India as an ornamental succulent (Bailey 1949, Behl et al. 1966). This species, and also Euphorbia tirucalli L. are often planted in foundation boxes in Florida. Since they outgrow such locations and have to be cut back, the trimmer is exposed to the free-flowing sap which can cause a rash and blisters, intense burning and temporary blindness (Morton 1958). Contact with the plant can produce severe oedematous and oozing dermatitis and also conjunctivitis; the face, scrotum, and hands are most commonly affected as is the case from exposure to Hura crepitans L. and Hippomane mancinella L. (Pardo-Castello 1923, 1962). The sap forms a rubbery clot about one minute after collection.

The sap is irritating to the human eye (Lampe & Fagerström 1968, Grant 1974). Crowder & Sexton (1964) observed kerato-conjunctivitis and uveitis from the sap of this plant. They exposed the eyes of dogs to the sap and to that of Euphorbia tirucalli, and observed corneal opacities which appeared after 24-36 hours and cleared in one to three weeks.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay. The irritants of this species are ingenol esters (Upadhyay & Hecker 1975, Evans & Kinghorn 1977).



Euphorbia lancifolia Schldl.
Ixbut

It seems that the plant is not strongly irritant since, in Guatemala, the leaves or stems are drunk in a herbal tea as a galactagogue in a dose of five leaves per cup, five cups per day (Morton 1981). Blohm (1962) refers to the purgative effects of an overdose.



Euphorbia lateriflora Schumach. & Thonn.

The juice is corrosive to flesh, acting as an escharotic, and has been used to produce white patches on the skin in order to simulate leprosy (Irvine 1961).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia lathyris L.
[syn. Tithymalus lathyris Hill]
Caper Spurge, Mole Plant, Myrtle Spurge

This European species which is grown as an annual, and is naturalised in the eastern United States and California, is sometimes planted to drive away moles or gophers. The first common name refers to a resemblance of the fruits to capers (Capparis spinosa L., fam. Capparaceae) with which they should not be confused. Persons who eat the fruits develop a severe burning sensation in the mouth and throat followed by purgation (Anon 1893).

The plant does not lose its toxicity on drying or storage (North 1967). The juice is irritant and, when applied to the skin, causes redness, itching, pimples, and sometimes gangrene (White 1887, Chesnut 1898, Pammel 1911, Lander 1926, Atkinson 1926). Cortelezzi (1937) reported a case of dermatitis from the plant.

The milky sap is irritant to the human eye (Lampe & Fagerström 1968, Grant 1974) producing kerato-conjunctivitis. Experimentally, guinea pigs but not rabbits were susceptible (Geidel 1962).

A proteolytic enzyme named euphorbain has been reported to occur in the latex of this species (Lennox & Ellis 1945, Lynn & Clevette-Radford 1983).

The plant contains irritant ingenol esters (Adolf & Hecker 1971, Fürstenberger & Hecker 1972) and 16-hydroxyingenol (Adolf & Hecker 1975a). Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently also reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia ledienii A.Berger

This thorny succulent species is described by Watt & Breyer-Brandwijk (1962) as being virulently poisonous.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of 12-deoxyphorbol and 12-deoxy-16-hydroxyphorbol esters in the plant (Evans & Kinghorn 1977).



Euphorbia leuconeura Boiss.
[syn. Euphorbia fournieri Rebut]
Madagascar Jewel, Spitting Palm, Spuckpalme

[Information available but not yet included in database]



Euphorbia linearis Retz

Pammel (1911) lists this species as being irritant.



Euphorbia marginata Pursh
[syn. Euphorbia variegata Sims]
Snow-on-the-Mountain, Ghostweed, Japanese Edelweiss

The plant was grown for its ornamental foliage in Australia but has been declared a noxious weed. The latex is irritant to the skin and eyes (Pammel 1911, Aplin 1966, Francis & Southcott 1967, Mair 1968, Everist 1972, Bailey & Bailey 1976). When the juice of the plant is placed on the skin, the area becomes erythematous almost immediately and there is a slight sensation of stinging at the contact site. The erythema disappears rapidly but is followed after a latent period by a constant, follicular, papulopustular irritative reaction (Shelmire 1940).

A man aged 50 years and a female aged 18 years developed marked swelling, erythema, and vesiculation a few hours after gathering and binding Euphorbia variegata. Application of the milky sap and an ether extract of the sap to the skin of the patients and of control subjects produced erythema and papules (Musger 1953). Samokhval & Krivchak (1974) also reported dermatitis from Euphorbia variegata.

In parts of Texas, the plant was formerly used for branding cattle, the juice having a caustic, blistering action on animals' skin. The plant is dangerous to handle, since contact with the copious milky juice causes swelling and an eruption (Orchard 1954). Honey derived from the plant is poisonous (Morton 1964).



Euphorbia megalantha Boiss.

Upadhyay et al. (1980a) ascribed the weak irritancy of this species to the presence of ingenol esters.



Euphorbia mellifera Aiton
[syn. Tithymalus melliferus Moench]

Pammel (1911) lists this species as being irritant.



Euphorbia memoralis R.A.Dyer

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex of this thorny succulent species in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia milii Des Moul.
Crown of Thorns, Christ Plant

A number of varieties and forms of this species are recognised (Jacobsen 1974), the two most commonly encountered being Euphorbia milii Des Moul. var. milii (syns Euphorbia milii Des Moul., Euphorbia bojeri Hook.) and Euphorbia milii var. splendens Ursch & Leandri (syn. Euphorbia splendens Bojer). Both of these varieties are commonly found in collections of succulent plants.

The plant is grown as a garden subject in western Australia. The stems are armed with sharp spines and the sap is corrosive to the skin and eyes, causing temporary blindness (Orchard 1954, Morton 1962a, Souder 1963, Aplin 1966, Behl et al. 1966).

Arnold (1968) in Hawaii, stated that from personal experience the sap of Euphorbia splendens was not particularly irritating to his own skin whereas that of Euphorbia tirucalli was extremely irritating. Patch tests with a young flowering greenhouse specimen were also carried out by Camm EL & Mitchell JC (1974 — unpublished observation). Fresh latex, crushed flowers, and bruised leaves were applied by 48 hour closed patch tests to the forearm flexures of three healthy white volunteers. No irritant effect was observed. Kinghorn & Evans (1975a) found the latex of Euphorbia milii collected in Nigeria to be only weakly irritant in a mouse ear irritancy assay.

The roots and stems yield ingenol esters, named milliamines (Uemura & Hirata 1971, 1973, Marston & Hecker 1983). Evans & Kinghorn (1977) reported the presence of ingenol esters in Euphorbia milii var. milii.



Euphorbia myrsinites L.
[syn. Tithymalus myrsinitis Hill]
Creeping Spurge

The plant, of Mediterranean origin, creeps around greenhouses and rock gardens throughout the United States. Children like to play with the milky latex and to rub it into their skin and on their toys (Editorial 1979).

Touton (1932) referred to dermatitis from the plant. Sierputowska & Sliwinska (1968) also refer to the irritant latex. In 20 patients, contact with the latex produced swelling and blistering of the skin, usually on the face, which appeared from two to eight hours after exposure and mostly cleared over the next four days (Spoerke & Temple 1979).

This species has been reported to contain esters of ingenol and 5-deoxyingenol (Evans & Kinghorn 1974, 1977) to which the irritant properties of the latex may be ascribed (Kinghorn & Evans 1975a, Upadhyay et al. 1980a).



Euphorbia neglecta N.E.Br.

The juice of this plant when introduced into the eye causes intense pain and inflammation, and on the forearm may raise a local rash (Raymond 1939).



Euphorbia neriifolia L.
[syns Elaeophorbia neriifolia A.Chev., Euphorbia ligularia Roxb.]
Cactus Hedge, Sweet Aloes, Hedge Euphorbia, Oleander-Leaved Euphorbia, Indian Spurge Tree, Sudu Sudu, Sesudu

This spiny plant is used as a hedge plant in India. The milky juice is locally rubefacient (Nadkarni 1976) and irritant to the skin and throat (Pammel 1911, Burkill 1935, Chopra & Badhwar 1940; Corner 1952, Souder 1963, Watt & Breyer-Brandwijk 1962, Behl et al. 1966); it has been used to destroy warts (Chopra 1965).

The sap is irritating to the human eye (Lampe & Fagerström 1968, Grant 1974).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia nivulia Buch.-Ham.
[syn. Euphorbia varians Haw.]

The latex is irritant (Chopra & Badhwar 1940, Behl et al. 1966).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia nubica N.E.Br.

Kinghorn & Evans (1975a) found the latex of this species to be non-irritant in a mouse ear irritancy assay.



Euphorbia obliqua Endl.

The sap is used in conjunction with charcoal for tattooing to produce blue marks (von Reis Altschul 1973).



Euphorbia officinarum L.

Pammel (1911) lists this species as being irritant. Rowley (1960) notes that the sap is irritant to wounds and to the eye.



Euphorbia orientalis L.
[syn. Tithymalus orientalis Hill]

Upadhyay et al. (1980a) found this species to be weakly irritant in a mouse ear irritancy assay.



Euphorbia paganorum A.Chev.

The latex of this thorny succulent species is very caustic (Dalziel 1937).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of 12-deoxyphorbol esters in the plant (Evans & Kinghorn 1975a, 1977).



Euphorbia palustris L.
[syn. Tithymalus palustris Hill]

Pammel (1911) lists this species as being irritant.

Kinghorn & Evans (1975a) found the latex of this species to be a weak irritant in a mouse ear irritancy assay. The activity has been ascribed to the presence of ingenol esters (Upadhyay et al. 1980a).



Euphorbia paralias L.
[syn. Tithymalus paralias Hill]
Sea Spurge

Gerarde (1636) wrote about the sea spurge (which he named Tithymalus paralius): "I took but one drop of it [the sap] into my mouth; which neuerthelesse did so inflame and swell in my throte that I hardly escaped with my life." His companion, Mr Rich, was similarly affected. Pammel (1911) lists the species as being irritant.

Sayed et al. (1980) have reported the presence of ingenol esters in this species.



Euphorbia pentagona Haw.

Kinghorn & Evans (1975a) found the latex of this species to be weakly irritant in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia peploides Gouan
[syn. Tithymalus peploides Klotzsch & Garcke]

Upadhyay et al. (1980a) demonstrated weakly irritant effects of this plant in a mouse ear irritancy assay but could find no ingenol esters.



Euphorbia peplus L.
[syn. Tithymalus peplus Gaertn.]
Petty Spurge

The latex is irritant (Pammel 1911, Bernhard-Smith 1923, Chopra & Badhwar 1940, Behl et al. 1966, North 1967, Everist 1972, von Reis Altschul 1973). This plant is one of the commonest weeds in gardens in Australia. The handling of the plant when weeding is a common source of irritation of the skin, particularly of the face, and of the eyes and lips (Francis & Southcott 1967). The plant produces buccal irritation in animals that eat it (Hurst 1942). Calnan (1975) reported dermatitis from the plant, and positive patch test reactions in all of six controls.

The juice has been employed for destroying rodent ulcers and warts (Maiden 1917). The milky sap (latex) is effective for treating solar keratoses (Wilkinson 1974) and basal cell carcinoma (Weedon & Chick 1976, Flood 1976) but this latter property cannot be regarded as being infallible (Beardmore 1976).

The sap is particularly irritating to the human eye (Lampe & Fagerström 1968, Grant 1974). Severe keratitis and corneal oedema resulted in a man from accidental instillation of the latex into the eye; recovery was complete in 10–12 days (Hartmann 1940b).

The dried sap of the plant has been observed to affect photographic plates at a distance of 1 cm (Chapman & Petrie 1912), but this could not be reproduced by Weedon & Chick (1976).

The irritant properties of this species (Kinghorn & Evans 1975a) may be ascribed to the presence of ingenol esters (Evans & Kinghorn 1977, Upadhyay et al. 1980a). Rizk et al. (1984) have reported the isolation of two irritant ingenane polyol esters, one being a 20-deoxyingenol ester, the other an ingenol ester.



Euphorbia petiolaris Sims
[syn. Tithymalus petiolaris Haw.]

Brache & Aquino (1978) note that this species is among the 14 commoner causes of plant contact dermatitis in the Dominican Republic.



Euphorbia pilosa L.
[syn. Tithymalus pilosus Hill]

Chopra & Badhwar (1940) note that this plant has an acrid and vesicant juice. Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay.



Euphorbia piscatoria Aiton

Pammel (1911) lists this species as being irritant.



Euphorbia pithyusa L.

Pammel (1911) lists this species as being irritant.



Euphorbia platyphyllos L.

Pammel (1911) lists this species as being irritant.



Euphorbia plumerioides Teijsm.

The leaves are used as fish poison, purgative, and vermifuge in New Guinea (von Reis Altschul 1973).



Euphorbia poissonii Pax
Tinya

The latex is a powerful irritant. Either this or one of the other cactiform species is used in dehairing hides (Dalziel 1937).

The irritancy of the latex was demonstrated by Kinghorn & Evans (1975a) using a mouse ear irritancy assay. Resiniferatoxin and tinyatoxin, two of the most irritant compounds known, have been isolated from this species (Evans & Schmidt 1976) together with several 12-deoxyphorbol (Schmidt & Evans 1976, Schmidt & Evans 1977a, Schmidt & Evans 1978, Evans & Schmidt 1979b) and 12-deoxy-16-hydroxyphorbol esters (Schmidt & Evans 1977b).



Euphorbia polyacantha Boiss.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay. The irritants of this species have been reported to be 12-deoxyphorbol esters (Evans & Kinghorn 1975b, 1977).



Euphorbia primulaefolia Baker

Pammel (1911) lists this species as being irritant. It has violently emetic properties (Uphof 1959).



Euphorbia pseudo-grantii Pax

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia pubescens Vahl

The plant is said to be very irritant (Pammel 1911).



Euphorbia pugniformis Boiss.
[syn. Euphorbia procumbens Mill.]

Pammel (1911) lists this species as being irritant. Watt & Breyer-Brandwijk (1962) note that the latex is violently emetic and purgative and seems undoubtedly to be highly irritant. These authors also refer to a report that Euphorbia procumbens has been used as a caustic on skin lesions.



Euphorbia pulcherrima Willd.
[syn. Poinsettia pulcherrima Graham]
Poinsettia, Flor de Pascua, Christmas Star, Mexican Flame Leaf, Lobster Plant

The plant is grown as a garden subject in Australia and Africa, and is cultivated for the Christmas trade as a houseplant in colder regions. The plant has small inconspicuous flowers, but attractive white, pink, or red bracts for which it is grown. Commercially grown cultivars are subjected to a strict short day regimen (an eight week period of no more than 10 hours of light in every 24 hours) and dwarfing chemicals to produce the short-stemmed, early winter flowering plants.

Brache & Aquino (1978) note that this species is among the 14 commoner causes of plant dermatitis in the Dominican Republic. According to Pammel (1911), Allen (1943), Morton (1958), Blohm (1962), Souder (1963), Aplin (1966), and Francis & Southcott (1967), the latex is irritant to the skin and eyes. It has been used as a depilatory in Mexico and Brazil (Watt & Breyer-Brandwijk 1962). Burkill (1935) notes that the latex has been reported to cause severe irritation in wounds, but that this has been stated to be quite unfounded. In a case reported by D'Arcy (1974), the eruption appeared about 24 hours after contact; allergy was suggested but patch tests were not recorded.

Patch tests were carried out with a young flowering greenhouse specimen by Camm EL & Mitchell JC (1974 — unpublished observation). Fresh latex, crushed flowers, and bruised leaves were applied by 48 hour closed patch tests to the forearms flexures of three healthy white volunteers. No irritant effect was observed. A similar result was obtained by Kinghorn & Evans (1975a) with the latex using a mouse ear irritancy assay.

Winek et al. (1979) studied the toxicology of poinsettia. They found the latex to be non-irritant to rabbit eyes; the diluted latex applied to rabbit skin produced mild irritation but if applied daily, produced moderate to severe dermatitis. Erythema and blistering was also produced following UV irradiation of areas treated with dilute latex. No skin sensitisation could be demonstrated in guinea pigs.

The latex of this species has given evidence of a sensitising capacity (Hausen & Schulz 1977b). Occupational contact dermatitis caused by Euphorbia pulcherrima in four floriculture workers was described by Santucci et al. (1983). Positive patch test reactions to the latex and to an aqueous extract of the leaves and latex were observed. Tests in controls were negative.



Euphorbia punicea Sw.

Pammel (1911) lists this species as being irritant.



Euphorbia ramosissima Hook. & Arn.

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Euphorbia regis-jubae J.Gay
[syns Euphorbia capazii Caball., Euphorbia obtusifolia subsp. regis-jubae (J.Gay) Maire, Tithymalus regis-jubae (J.Gay) Klotzsch & Garcke]
King Juba's Euphorbia, Milky Tree Spurge, König Jubas Wolfsmilch

Incorrectly citing Greshoff (1909) as the source of his information, Pammel (1911) listed this species as being irritant.



Euphorbia resinifera Berg

Wimmer (1926) referred to the spines of Euphorbia resinifera as a possible cause of mechanical injury.

This species is one of the sources of Gum Euphorbium or Gummi Resina; other sources include Euphorbia canariensis L., Euphorbia officinalis L., and Euphorbia antiquorum L. (Uphof 1959). The latex is collected by making incisions in the stem and is then dried. The taste is extremely acrid and persistent and the dust excites violent sneezing (Burkill 1935, Wren 1975, Todd 1967). Dioscorides and Pliny described the method of collecting the juice so as to prevent irritation of the hands and face (Dispensatory 1884). The men who collect the exuded dried latex muffle their faces to prevent the dust getting into their mouths and nostrils. The action upon man is first to cause sneezing, then irritation of the skin and mucous membrane, vomiting, diarrhoea and death (Burkill 1935). The drug is no longer used medicinally but serves to make an anti-fouling paint for ship's bottoms. The plant is used to make a vesicant ointment in veterinary medicine (Perrot & Paris 1971).

The latex was used to destroy warts (Bigelow 1817) and as an ingredient of a rubefacient plaster. Pammel (1911) lists Euphorbia resinifera as being irritant. Nadkarni (1976) refers to its counter irritant properties.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of resiniferonol, ingenol, and 12-deoxyphorbol esters in the plant (Evans & Kinghorn 1977). Resiniferatoxin, one of the most potent irritants known, has been isolated from this species (Hergenhahn et al. 1975). Several irritant 12-deoxyphorbol & ingenol esters have also been found in euphorbium derived from this species (Hergenhahn et al. 1974).



Euphorbia rigida Bieb.
[syns Euphorbia biglandulosa Desf., Tithymalus biglandulosa Haw.]

Smirnov & Efremov (1970) have reported dermatitis from this species.

The latex is irritant in the mouse ear irritancy assay from its content of ingenol esters (Evans & Kinghorn 1974, 1977, Kinghorn & Evans 1975a). Esters of 4-deoxyphorbol, ingenol, and 20-deoxyingenol have subsequently been identified from this species (Falsone & Crea 1979, Falsone et al. 1982).



Euphorbia robbiae Turrill

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia rothiana Spreng.

This species has irritant properties (Chopra & Badhwar 1940, Behl et al. 1966, Sood et al. 1971, Sofat et al. 1972).



Euphorbia royleana Boiss.
[syn. Euphorbia pentagona Royle]
Churee, Royle's Spurge, Sullu Spurge

Forming a shrub or a small tree up to 5m high with whorled spiny branches bearing deciduous fleshy leaves, this species is common on the outer dry slopes of the western Himalayas, chiefly at altitudes of 3,000–5,000 feet. It is also commonly grown as hedging in sub-Himalayan tracts and adjacent plains (Chopra et al. 1960). The plant should not to be confused with Euphorbia pentagona Haw.

This species was listed by Pammel (1911) as reportedly irritant. Chopra & Badhwar (1940) and Behl et al. (1966) noted that various Euphorbia species, including Euphorbia royleana have an acrid and vesicant juice. And Chopra et al. (1960), citing earlier literature, noted that the fresh latex, which has a rich sweet odour, is acrid and possesses cathartic and anthelmintic properties. They noted also that it is liable to cause dermatitis and is reported to be injurious to the eyes.

However, in a test for irritant potential carried out by Bhalme & Pasricha (1986) on 10 patients with contact dermatitis, performed by rubbing the freshly exposed pulp of the plant 10 times on the forearm and observing for 48 hours, no skin reaction was observed. When subsequently patch-tested "according to standard techniques using the juice and the pulp", one of the 10 patients experienced a 2+ reaction to the juice and 4 of the 10 patients experience reactions (1/10 4+; 1/10 3+, & 2/10 1+ ) to the pulp. It is not clear whether the reactions observed were of an allergic aetiology. It is possible that the reactions these authors observed were actually delayed irritant reactions produced under occlusion. Sofat et al. (1972), in an investigation of three patients who had presented with keratitis following accidental introduction of the latex of Euphorbia royleana into the eye, similarly noted that the hands of two collectors, which had become thoroughly smeared with the milky latex, showed no dermatotoxic reaction even though the latex had remained in contact with the skin for more than three hours.

In a mouse ear irritancy assay of the crude latex or herb extracts from 60 species of Euphorbia, tested in dilution series prepared with acetone, Kinghorn & Evans (1975) found the latex from Euphorbia royleana to be irritant. These authors noted that the inflammation produced by the majority of species reached a maximum effect after 24 hours, whilst some produced short-lived irritant effects reaching a maximum after 4 hours. A later study by these authors (Evans & Kinghorn 1977) related the irritancy to the presence of ingenol esters in the context that the irritant properties of ingenol-3-esters had already been established (Opferkuch & Hecker 1974, Adolf & Hecker 1977). Rizk et al. (1984) reported that an extracted resin from this species demonstrated pronounced pro-inflammatory activity in a mouse ear irritancy assay. Li et al. (2009) later reported the isolation and characterisation of two ingenol tri- / tetra-esters (ingenol 3-angelate 5,20-diacetate and 5,17,20-triacetyl-3-O[(Z)-2-methyl-2-butenoyl]-17-hydroxyingenol) from the aerial parts of the plant.

Whilst the skin irritant activity of this species can be ascribed to ingenol esters present in the latex, the reported variability of the irritant potency suggests that [geographic ?] chemovariation occurs. Another possible explanation for this variability is that this species contains "cryptic irritants" (see Upadhyay & Hecker 1976, Upadhyay et al. 1980) that become activated to a greater or lesser extent by hydrolysis on or in the skin following contact. However, the medical literature points to eye injury caused by accidental splashing of the eyes with the latex as being more likely to occur than dermatitis. Case reports describe intensely painful acute conjunctivitis with corneal ulceration and iridocyclitis, which can lead to sight loss. In the three cases described by Sofat et al. (1972), all three patients had used home remedies for first aid without effect. After first irrigating with tap water, one had used the juice from Sedum multicaule Wall. ex Lindl. (fam. Crassulaceae) and human milk, another had instilled human milk and honey, and the third had instilled the juice from banana stems (fam. Musaceae). A fourth patient described by Sood et al. 1971, who instilled the juice from Sedum multicaule 24 hours after splashing the juice into his eyes but without initial irrigation with tap water, claimed to have experienced slight relief. See also Aeonium lindleyi Webb & Berthel., fam. Crassulaceae.



Euphorbia schlechtendalii Boiss.

This species is said to be very poisonous, caustic, and used to poison fish (von Reis Altschul 1973).



Euphorbia segetalis L.
[syn. Tithymalus segetalis Lam.]

Upadhyay et al. (1980a) ascribe the irritancy of the latex of this species to the presence of ingenol esters.



Euphorbia seguieriana Necker
[syn. Euphorbia gerardiana Jacq.]

Pammel (1911) lists this species as being irritant. The irritants are ingenol esters (Upadhyay et al. 1976a, 1976b, 1980a).

Honey derived from the nectar of this species was found to have moderately irritant properties associated with the presence of ingenol triesters (Upadhyay et al. 1980b).



Euphorbia serrata L.
[syn. Tithymalus serratus Hill]

The irritants of this species are ingenol esters (Upadhyay et al. 1976a, 1976b, 1980a).



Euphorbia serrulata Reinw.

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Euphorbia sibthorpii Boiss.

Pammel (1911) lists this species as being irritant. Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol and 5-deoxyingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia sieboldiana C.Morren & Decne.

Pammel (1911) lists this species as being irritant.



Euphorbia sikkimensis Boiss.

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of ingenol esters in the plant (Evans & Kinghorn 1977).



Euphorbia stenoclada Baill.

Kinghorn & Evans (1975a) found the latex of this species to be non-irritant in a mouse ear irritancy assay.



Euphorbia striata Thunb.

Handling the fresh plant can produce irritation of the skin (Steyn 1928).



Euphorbia striatella Boiss.
[syn. Tithymalus striatus Klotzsch & Garcke]

Upadhyay et al. (1980a) ascribed the strong irritancy of this species to the presence of ingenol esters.



Euphorbia sudanica A.Chev.

The latex of this thorny succulent species is caustic (Dalziel 1937).



Euphorbia szovitsii Fisch. & C.A.Mey.
[syn. Tithymalus szovitsii Klotzsch & Garcke]

Upadhyay et al. (1980a) ascribed the weak irritancy of this species to the presence of ingenol esters.



Euphorbia terracina L.
False Caper, Geraldton Carnation Weed

The milky sap of this plant, which has a repulsive smell, causes inflammation of the eyes and of the softer portions of the human body when the plants are pulled by hand and the workers are heated (J. Agr. S. Aust. 1947). Orchard (1954) refers to irritation by the plant. The plant is also said to have no, or only a faint scent (Cleland 1952).



Euphorbia tetragona Haw.

The latex of this thorny succulent species is irritant and blisters the skin, and produces severe irritation and even blindness when accidentally applied to the eyeball. However, the latex has also been utilised for the manufacture of chewing gum (Watt & Breyer-Brandwijk 1962).



Euphorbia thomsoniana Boiss.

This species is irritant (Chopra & Badhwar 1940, Behl et al. 1966).



Euphorbia tirucalli L.
[syn. Euphorbia viminalis Mill.]
Naked Lady, Pencil Tree, Indian Tree Spurge, Milk Bush, Rubber Hedge, Finger Tree, Tulang Tulang, Tentulang

This plant and also Euphorbia lactea Haw. are often planted in foundation boxes in Florida. They outgrow such locations and have to be cut back exposing the trimmer to the free-flowing sap which can cause skin eruptions and blisters, intense burning, and temporary blindness (Morton 1958). The plant is grown as a garden subject in Western Australia, as a common "rubber hedge" of Southern Zimbabwe planted around African Kraals as a deterrent to marauders, as a live hedge plant, and on graves in Malawi where it discourages browsing animals. Planted in India as a cattle fence, it used to be a formidable obstacle to cavalry. From India it has been reported to be used by criminals to destroy the eyes of domestic animals; it is established there as a common road-side tree.

The latex is violently irritant to the skin and eye (Pammel 1911, Burkill 1935, Raymond 1939, Chopra & Badhwar 1940, Corner 1952, Williamson 1955, Oliver 1959, Everist 1962, Watt & Breyer-Brandwijk 1962, Souder 1963, Aplin 1966, Behl et al. 1966, Francis & Southcott 1967, Arnold 1972, Grant 1974, Nadkarni 1976, Morton 1981). Washing with water will not remove the irritant latex which forms a rubbery clot after one minute's exposure to the air (Crowder & Sexton 1964, Everist 1962). Strobel et al. 1978 described a case of widespread dermatitis in an 8 year old who had played in a hedge of Euphorbia tirucalli and come into contact with the abundant latex. Kerato-conjunctivitis from the plant (Crowder & Sexton 1964) is noted under Euphorbia lactea Haw.

Roe & Field (1965) tested the latex of nine Euphorbia species and found that of Euphorbia tirucalli to be the most irritant and cocarcinogenic for mouse skin. Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of 4-deoxyphorbol esters in the plant (Evans & Kinghorn 1977). Ingenol and 4-deoxyphorbol esters have been isolated from this species (Fürstenberger & Hecker 1977a, 1977b, Kinghorn 1979b). Interestingly, Baslas & Gupta (1982, 1983a, 1983b) have reported the isolation of a number of compounds from Euphorbia tirucalli bark and roots that have previously been reported from Euphorbia poissonii Pax.



Euphorbia tithymaloides L. subsp. parasitica V.M.Steinm.
[syns Pedilanthus latifolius Millsp. & Britton, Pedilanthus parasiticus Klotsch & Garcke, Pedilanthus tithymaloides Poit. subsp. parasiticus Dressler]
Christmas Candle, Redbird Flower

The stems, leaves and roots of Pedilanthus latifolius possess a very caustic milky juice which can produce severe irritation of the skin (Roig y Mesa 1953).



Euphorbia tithymaloides L. subsp. tithymaloides
[syns Pedilanthus fendleri Boiss., Pedilanthus gritensis Zahlbr., Pedilanthus tithymaloides Poit.]
Japanese Poinsettia, Milkbush, Redbird Cactus, Redbird Flower, Slipper Plant, Christmas Candle, Candedilla, Lady's Slipper

The milky sap is caustic and may cause rash and even blistering of the skin. It is acutely painful and injurious in the eye (Pammel 1911, Allen 1943, 1981, Blohm 1962, Martinez 1969). Some horticultural varieties of the plant have irritant properties (Behl et al. 1966).

The milky sap of Pedilanthus tithymaloides Poit. is acutely painful and injurious to the eye (Morton 1962a, Lampe & Fagerström 1968, Grant 1974).

Upadhyay & Hecker (1974) found the plant to be non-irritant when screened for irritancy.



Euphorbia triangularis Desf.
[syn. Euphorbia evansii N.E.Br.]

Honey produced from the nectar of this thorny succulent species is said to be irritant but the latex has been used for making rubber and chewing gum and is described as being patently non-irritant (Watt & Breyer-Brandwijk 1962).

The irritants of this species are 12-deoxyphorbol esters (Gschwendt & Hecker 1969, Gschwendt & Hecker 1974). Kinghorn & Evans (1975a) also demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of 12-deoxyphorbol esters in the plant (Evans & Kinghorn 1977).



Euphorbia trigona Mill.
[syn. Euphorbia hermentiana Lemaire, Euphorbia trigona Haw.]
Friendship Cactus, African Milk-Bush, Dreikantige Wolfsmilch

The latex of this Indian shrub is irritant but less so than that of its close relatives (Burkill 1935). Chopra & Badhwar (1940) and Souder (1963) list Euphorbia trigona among spurges that cause an acute dermatitis on contact with their sap or latex.

Euphorbia hermentiana has been sold in plant stores in the Chicago area, and was being given away by a bank as an incentive to open a savings account. In a clinical investigation, the latex produced an irritant follicular dermatitis in open tests on the forearms of volunteers, but vesiculation and bullae with residual desquamation and hyperpigmentation in closed tests (Worobec et al. 1981). The dermatitic constituents were subsequently identified as esters of ingenol and 16-hydroxyingenol (Lin et al. 1983).

There are several references in the literature to Euphorbia trigona Roxb., a name first published in the Flora of India [Flora Indica] in 1832. This is an illegitimate name that was originally applied to a plant now recognised as Euphorbia lacei Craib, which had originally been introduced into India from the Molucca Islands. However, the name Euphorbia trigona Roxb. has also been applied to Euphorbia trigona Mill., an African species that it closely resembles, and which also has been introduced into, and is now considered endemic in India.



Euphorbia unispina N.E.Br.
Candle Plant, Tinya

The latex of this thorny succulent is a powerful irritant (Dalziel 1937).

Kinghorn & Evans (1975a) demonstrated the irritancy of the latex in a mouse ear irritancy assay, and subsequently reported the presence of resiniferonol and 12-deoxyphorbol esters in the plant (Evans & Kinghorn 1977). Resiniferatoxin and tinyatoxin, two of the most irritant compounds known, has been isolated from this species (Hergenhahn et al. 1975, Schmidt & Evans 1975), together with several esters of 12-deoxyphorbol (Schmidt & Evans 1977a).



Euphorbia venefica Trémaux

Pammel (1911) lists this species as being irritant.



Euphorbia venenata Marloth

This thorny succulent species can produce severe inflammation of the mucosae (Watt & Breyer-Brandwijk 1962).



Euphorbia verrucosa Lam.

Pammel (1911) lists this species as being irritant.



Euphorbia virosa Willd.

The latex of this species is said to be irritant and virulently poisonous (Watt & Breyer-Brandwijk 1962).



Excoecaria agallocha L.
Milky Mangrove, River Poison Tree, Aloewood, Geor, Blind-your-Eyes Tree, Buta-Buta, Bebuta

The milky juice in the green bark is strongly irritant (Ridley 1898, Pammel 1911, Gimlette 1929); an axe blow may bespatter the wood cutter with it causing blisters on the bare skin and irritation of the eyes. Experienced wood cutters remove the bark before felling a tree so that no harm results (Burkill 1935). Because of its irritancy, the tree is rarely cut in Sabah (Burgess 1966). The sap is known to be irritant in Australia (Cleland 1914, Logan 1925, Maiden 1904a, Maiden 1909b, Gardner & Bennetts 1956, Hurst 1942, Cleland & Lee 1963, Francis & Southcott 1967), in Thailand (Smitinand & Scheible 1966), in India (Chopra & Badhwar 1940, Behl et al. 1966), in Samoa (Gimlette 1929), and on Guam Island (Souder 1963). Volatile emanations from the tree are also said to be irritant. A single drop of sap getting into the eye can produce severe irritation; the eye may be completely destroyed (Gimlette 1929).

Diseased wood is fragrant and aromatic, and is sold as bastard aloeswood; it burns with a scent that is stronger than benzoin. The wood loses its fragrance in a few years (Burkill 1935). Burgess (1966) also refers to its use as an incense wood and notes that in areas where other wood is in short supply, that of Excoecaria agallocha is used for making packing cases, clogs, matches, toys, and furniture.

The wood is said to irritate the skin and eyes even when it is dry (Lewin 1928). The smoke from the burning wood is very irritating so the wood is little used for firewood; workmen making charcoal from it are said to suffer (Burkill 1935, Souder 1963).

The sap has been used in folk medicine as a caustic application for chronic ulcers in Australia (Cleland 1914), Malaysia (Burkill 1935) and in India where it is known as tiger's milk (Behl et al. 1966).

Children in Queensland have used the sap of this species for chewing gum in mistake for the sap of the Moreton Bay fig (Ficus macrophylla Desf., fam. Moraceae) with fatal results (Logan 1925, Cleland & Lee 1963, Francis & Southcott 1967).

Ohigashi et al. (1974) isolated and characterised a piscicidal daphnane polyol orthoester from the latex, to which the irritant properties may be ascribed.



Excoecaria bantamensis Müll.Arg.
[syn. Excoecaria macrophylla J.J.Sm. ex Koord. & Valeton]

Excoecaria macrophylla is dreaded by natives of the Philippine Islands because it is strongly irritant to the skin (Burkill 1935).



Excoecaria cochinchinensis Lour.

Burkill (1935) notes that the latex kills fish more readily than that of Excoecaria agallocha L. von Reis Altschul (1973) noted from an herbarium specimen of Excoecaria cochinchinensis var. viridis that the latex provokes itching.



Excoecaria dallachyana Benth.
Bush Poison Tree

The milky sap is irritant to the skin and erosive to the cornea (Burkill 1935, Hurst 1942, Everist 1972).



Excoecaria grahami Stapf
[syn. Sapium grahami Prain]

This species is irritant (Burkill 1935). The latex of the root has vesicant and escharotic properties (Dalziel 1937); when ground with a little water, it produces red or black marks on the face, causing swelling and ultimately tattoo-like marks. When applied to fresh tribal markings, it ensures scarification. The juice from the crushed leaves is less irritant but is used by small boys to raise blisters (Irvine 1961).



Excoecaria indica Müll.Arg.
[syns Sapium indicum Willd., Stillingia indica Baill.]

The fruits are used by Malay children to play "marbles". The seeds can be eaten when quite ripe but care should be taken to put nothing more than the seed into the mouth, as the latex which is in the fruit-wall, is caustic (Burkill 1935, Irvine 1961). The latex blisters the skin (Perry & Metzger 1980, Burkill 1935).

Irritant esters of phorbol and related polyols have been reported from this species (Evans & Taylor 1983).



Excoecaria oppositifolia Griffith

This tree of upper Burma is probably irritant (Burkill 1935).



Excoecaria parvifolia Müll.Arg.
Gutta Percha Tree

The sap [= latex] is acrid and drastically irritant to the human skin and eye and to the mouths of humans and sheep (Maiden 1904a, Maiden 1909b, Logan 1925, Hurst 1942, Cleland & Lee 1963). Cleland (1914) alludes to the fact that the irritant compounds present in the latex may volatilise.



Excoecaria venenifera Pax

The milky juice is very poisonous (e.g. to camels) and particularly injurious to the eyes (Lewis & Elvin-Lewis 1977).



Fahrenheitia pendula Airy Shaw
[syn. Croton pendulus Hassk.]

The sap is irritating and painful (Airy Shaw 1975).



Fontainea pancheri Heckel

The tree contains a remarkable poison, and is used for poisoning fish (von Reis Altschul 1973).



Grimmeodendron Urb.

Two species are found in the West Indies. Kinghorn (1979a) reported skin irritancy from a Grimmeodendron species.



Grimmeodendron jamaicense Urb.

von Reis & Lipp (1982) note from an herbarium specimen that this plant is known locally as "burn-eye".



Gymnanthes lucida Sw.
[syns Ateramnus lucidus (Sw.) Rothm., Excoecaria lucida (Sw.) Sw., Sebastiania lucida (Sw.) Müll.Arg.]
Crab Bush, Crab Wood, False Lignum-Vitae, Oysterwood

The wood is listed by Hausen (1970), who cites Bernhard-Smith (1923) and Pennington (1958), as being injurious. According to Morton (1981), references in the literature to this species having toxic milky sap must be due to confusion of this tree with the closely related Hippomane mancinella L..



Hevea brasiliensis Müll.Arg.
Pará Rubber

This tree is the source of the best rubber which is the coagulated milky latex. Pirilä (1947) recorded a case in which there was simultaneous sensitivity to caoutchouc (rubber), Swedish turpentine and cymene.

Contact dermatitis to rubber is common and is usually due to substances used in its manufacture (Wilson 1960). Weinstein & Fellner (1979), for instance, report a case of sensitivity to rubber bands, with a positive patch test reaction to tetramethylthiuram. Cronin (1980) provides a recent review of such "rubber" dermatitis. Sensitivity to natural, unprocessed rubber latex is rare. Nutter (1979) described a case of contact urticaria elicited by natural rubber. This was confirmed by testing with a finely cut leaf sample of Hevea brasiliensis. Meding & Fregert (1984), Galinsky & Kleinhans (1982), and Förström (1980) described contact urticaria to natural rubber gloves.

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Hippomane mancinella L.
Manchineel, Beach Apple, Arvoreda Morte, Manzanillo

A number of other colloquial names are listed by Morton (1981) and Earle (1938).

This tree, perhaps the most notorious of all irritant trees, has acquired an extensive mythology (Bodeau 1936, Earle 1938). The species name is derived from the Latin American name manzanillo - "little apple". The early Spanish explorers discovered that the fruits were poisonous (Standley 1927). He stated that this tree is the worst of all the euphorbiaceous trees but happily it never grows outside a narrow belt fringing the seashore. The tree has been largely eliminated in southern Florida except from the Everglades National Park; persons wishing to fish in certain parts of that area are permitted to do so only after proving to Park authorities that they can recognise the manchineel tree and so avoid poisoning (Morton 1958). The tree grows to about 6 metres in height and spreads about 6 metres. It is sought by the unwary for shelter and even rain falling from the tree can cause irritation. Wood cutters char the bark before cutting the tree down (Barham 1794, Allen 1943).

The wood is used locally for turnery and cabinet-work, but the sawdust causes rhinitis and cough and some men refuse to work with it (Earle 1938). Workers cutting down the tree were affected by blistering of the skin. Friction of the parts affected with the buds and young leaves of the white cedar (Tabebuia heterophylla Britton), Macfadyena unguis-cati A. Gentry, or other members of the family Bignoniaceae, which grow in close proximity to the tree were said to be an effective antidote (Hamilton 1846, Pammel 1911, Standley 1926b). The smoke of the wood, if used for fuel, is intensely irritating to the eyes (Allen 1943, Standley 1927, Dahlgren & Standley 1944). The wood, if thoroughly dried, is said to lose its irritant properties and is used for utensils (Standley 1927).

All parts of the plant contain a caustic milky juice which produces severe burning and swelling on contact with the skin and temporary blindness if rubbed into the eyes (Allen 1943, Dahlgren & Standley 1944). Pammel (1911) cited early authors in describing the properties of the tree. Grana (1946) reported 13 cases of acute conjunctivitis and dermatitis due to contact with the tree on beaches. According to Pardo-Castello (1962), dermatitis from contact with the plant affects principally the face, scrotum, and hands. Earle (1938), Satulsky (1943), Satulsky & Wirts (1943), and Snow & Harley (1944) provided clinical descriptions. Soldiers training in the West Indies during World War II developed bullous dermatitis and conjunctivitis after accidental contact with the sap. Dermatitis from the tree is known in Barbados and in Cuba (Sheard 1974). It is difficult to rationalise the observation of Satulsky & Wirts (1943) that one individual in a detachment of 60 soldiers could handle the plant material and rub the latex into his skin with impunity.

Biting into the highly poisonous fruit (Pammel 1911) causes large blisters on the cheeks and lips which become extremely swollen. The sap was used by exiled prisoners in French Guiana to provoke dermatitis and conjunctivitis (Allen 1943). Persons also used it on their backs to simulate the effects of a beating (White 1887).

Irritation of the penis followed handling the plant (Wedd 1937). Perianal dermatitis followed the use of the leaves as toilet paper (Satulsky & Wirts 1943). Five sailors developed dermatitis after a beach barbeque under the trees (Lowe 1974).

The irritant can be effectively removed from the skin by soap and water within 30 minutes of contact, or more traditionally by plain seawater as the tree is usually found on or near beaches (Hamilton 1846, Snow & Harley 1944).

The seeds are poisonous when ingested (Caddy 1894, Lewis & Elvin-Lewis 1977); the plant is said to be violently emetic (von Reis Altschul 1973).

Adolf & Hecker (1975b) isolated a number of irritant tigliane and daphnane polyol esters from the latex.



Homalanthus acuminatus (Müll.Arg.) Pax
[syn. Carumbium acuminatum Müll.Arg.]

Citing earlier sources, Uhe (1974) noted that the wood dust is irritating to the nose and throat, frequently resulting in bleeding.



Homalanthus nutans (G.Forst.) Guill.
[syns Carumbium nutans (G.Forst.) Müll.Arg., Croton nutans G.Forst., Stillingia nutans (G.Forst.) Geiseler]

From a survey of the medicinal plants of Samoa and also citing earlier sources, Uhe (1974) noted that the leaves are used to dress circumcision wounds, sores, and cuts, and also elephantiasis, adding that the plant is poisonous and an irritant. The leaves have been used as a fish poison in the Solomon Islands (von Reis Altschul 1973).



Homalanthus populneus (Geiseler) Pax
[syns Carumbium populneum (Geiseler) Müll.Arg., Stillingia populnea Geiseler]

The plant has been used as a fish poison in the Philippines (von Reis Altschul 1973).



Hura crepitans L.
[syns Hura brasiliensis Willd., Hura senegalensis Baill.]
Hura, Assacu, Sandbox Tree, Possentri, Possumwood, Jabillo, Sablier, Ceiba Blanca, White Cedar

The common names possen- and possum- are corruptions of poison (Record & Mell 1924). The name sandbox tree refers to the use of the seed pods in earlier times both as as sand-filled receptacles for goose quills used as pens and as containers of fine sand to expedite drying of ink on newly written papers (Menninger 1967).

This species is among the 14 commoner causes of plant contact dermatitis in the Dominican Republic (Brache & Aquino 1978).

"The fellers, as they cut them down, are very careful of their eyes; and those that have cipers [kerchiefs], put it over their faces; for if any of the sap fly into their eyes, they become blind for a month." (Ligon 1673). Men engaged in felling the tree developed swelling of the face and hands from contact with the acrid sap (Allen 1943). The sap from broken leaves, branches and from bark is vesicant to the skin and the sawdust is irritant to carpenters (White 1887, Pardo-Castello 1923, Standley 1927, Chopra & Badhwar 1940, Allen 1943, Kerharo & Bouquet 1950, Blohm 1962). Arnold (1968), in Honolulu, did not find the plant noticeably irritant to his own skin. The sap is said to be milky (White 1887, Standley 1927) but Morton (1972b, 1981) in Florida found it to be translucent, yellowish, and sticky but not milky. The segments of the woody fruits can cause dermatitis when they are used in bracelets and necklaces (Morton 1958).

The bark of the young tree is studded with stout prickles. The fruits explode violently when ripe; the noise they make gives rise to the West Indian name "monkey's dinner bell". The noisy explosion of the ripe, dry pods showers by-standers with seeds and sharp-pointed segments sometimes to a distance of 60 metres. The tree thus "stabs, poisons, and shoots" (Barrett 1956).

The wood exported to Europe has caused dermatitis (Hausen 1981). It was one of the first toxic woods to be chemically investigated. Boussingault & Rivero (1825), working in Bogota, found a vesicant essential oil in the latex, the vapour from which inflamed their faces severely while it was being boiled down.

Richet (1909, 1910) studied anaphylaxis provoked in animals by an albuminoid extract of the latex which he called crepitine, but this was not the irritant principle. Jaffé (1943) reported the isolation of a proteolytic enzyme, named hurain, from the latex.

The juice and seeds cause violent vomiting and diarrhoea when ingested (Chopra & Badhwar 1940, Lewis & Elvin-Lewis 1977, Morton 1981).

The principal irritant constituent of Hura crepitans would appear to be the daphnane derivative huratoxin which was isolated and identified by Sakata et al. (1971a, 1971b).



Hura polyandra Baill.

The milky juice is used for poisoning fish; the seeds are violently purgative (Uphof 1959).



Hyaenanche globosa Lambert
[syn. Toxicodendrum capense Thunb.]

The genus Hyaenanche Lambert & Vahl is monotypic. The species is found in southern Africa.

Hausen (1970) cites Anon (1940) and Briggs (1946) for an injurious effect of the wood and Henry (1920) for chemical aspects.



Jatropha L.

One hundred and seventy-five species are principally found in tropical and subtropical regions but also in North America and southern Africa.

Species bearing stinging hairs, and at one time included within this genus, are now considered to belong to a distinct genus, Cnidoscolus Pohl.



Jatropha curcas L.
Physic Nut, Purging Nut, Jarak, Jarak Pagar, Jarak Belanda

The tree is used in hedges and planted in graveyards (Barrett 1956, Irvine 1961). The sap of the tree turns brown and brittle when dried, stains linen, and can be used as a marking ink (Oliver 1961).

The greenish viscid juice and pounded leaves are rubefacient (Watt & Breyer-Brandwijk 1962, Smitinand & Scheible 1966) and styptic and can cause inflammation of the eyes (Irvine 1961). The sap can cause dermatitis (Hurst 1942, Morton 1958, Watt & Breyer-Brandwijk 1962, Souder 1963) but is used by children in Malaysia and in Africa for blowing bubbles (Burkill 1935, Irvine 1961). The seeds contain a poison that acts on the skin producing redness and pustules on the skin (Burkill 1935, Smitinand & Scheible 1966). They are drastically purgative when ingested and have been used as a vermifuge (Chopra & Badhwar 1940, Lewis & Elvin-Lewis 1977, Morton 1981). Toxicity varies from tree to tree, some bearing apparently harmless seeds, others violently purgative (Morton 1958). Burkill (1935) refers to two races in Malaysia, one with dark seeds and one with pale seeds. Frequent eating of roasted seeds, even from an apparently harmless tree, can produce sores in the mouth (Morton 1958, Morton 1981). The seed oil, known as Chinese castor oil, hell oil, or Oleum Infernale has been used for soap and illumination. It is violently purgative. The husk of the seeds contains a toxalbumin, curcin, related to ricin of Ricinus communis L. (Webb 1948a).

Wimmer (1926), possibly referring to Jatropha curcas, made mention of the irritating hairs of Jatropha cereus, a name of no botanical standing. Watt & Breyer-Brandwijk (1962), citing an earlier source, noted that the stiff hairs of the fruit [of Jatropha curcas] cause great pain for twenty-four hours or longer, sometimes accompanied by fever. These reports are unreliable and must refer to a different plant because the fruits of Jatropha curcas do not bear such hairs (Hyde et al. 2022).

Adolf et al. (1984) showed the presence of 12-deoxy-16-hydroxyphorbol esters in the seed oil and demonstrated their irritancy using a mouse ear assay.



Jatropha glandulifera Roxb.

Nadkarni (1976) noted that this species has counter-irritant juice. Chopra & Badhwar (1940) referred to the violently purgative property of the species.



Jatropha gossypifolia L.
Spanish Physic-Nut Tree, Wild Physic Nut, Belly-Ache Bush, Wild Cassava, Cotton-Leafed Physic-Nut, Jarak Merah, Jarak Hitam, Jarak Beremah, Jarak Kling

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex. A yellowish-brown substance in the pith of old stems is used to provoke sneezing (Quisumbing 1951, Irvine 1961). The seeds are toxic but less so than those of Jatropha curcas (Oakes & Butcher 1962). They do, nevertheless, possess a drastically emetic and purgative oil (Chopra & Badhwar 1940, Morton 1958, Morton 1981).

Morton (1981) records a variety of local medicinal uses of various parts of the plant, including the use of the roots as an application for dermatitis caused by Hippomane mancinella L.

Adolf et al. (1984) demonstrated the presence of irritant 12-deoxy-16-hydroxyphorbol esters in this species.



Jatropha integerrima Jacq.
[syns Adenoropium integerrimum Pohl, Jatropha hastata Jacq., Jatropha pandurifolia Andrews]
Peregrina, Spicy Jatropha

[Information available but not yet included in database]



Jatropha multifida L.
Coral Plant, French Physic Nut, Spanish Physic Nut

Pammel (1911) and Souder (1963) list this species as being irritant.

The oil from the seeds, named pinhoen oil, has properties similar to those of Jatropha curcas L. (Chopra & Badhwar 1940, Burkill 1935, Morton 1958). As little as one seed will cause violent vomiting and purging if ingested (Morton 1981).

Adolf et al. (1984) demonstrated the presence of irritant 16-hydroxyphorbol esters in this species. There is also some support for the occurrence of benzyl glucosinolate in the latex of this species (Kjær 1960), a source of the potentially allergenic mustard oil benzyl isothiocyanate. See also Cruciferae



Jatropha nana Dalz. & Gibson

In Indian indigenous medicine, the juice is used as a counter-irritant in ophthalmia (Nadkarni 1976).



Jatropha podagrica Hook.
Gout Stick

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex. Adolf et al. (1984) demonstrated the presence of irritant 16-hydroxyphorbol esters in this species.



Mabea Aubl.

All the Mabea species of the section Taquari possess long, hollow, sarmentose branches, and are infested by ants (Wheeler 1942).



Macaranga Thouin

About 280 species are found in tropical Africa, Madagascar, Indomalaysia, Australia and the Pacific region. Some yield kino gum (Burkill 1935).

A number of species have been reported to have hollow stems inhabited by ants (Ridley 1910, Bequaert 1922, Corner 1952, Menninger 1967, Airy Shaw 1975, Rickson 1980):

Macaranga beccariana Merr.
[syn. Macaranga hypoleuca Müll.Arg. var. borneensis Hutchinson]
Macaranga caladifolia Becc.
Macaranga cornuta Müll.Arg. — Horned Ant-Mahang
Macaranga dibeleensis De Wild.
Macaranga formicarum Pax & K.Hoffm.
Macaranga hosei King — Hose's Mahang
Macaranga hullettii King
Macaranga hypoleuca Müll.Arg. — White Mahang, Mahang Puteh
Macaranga kingii Hook.f. — Devil's Mahang
[syn. Macaranga insignis Merr.]
Macaranga maingayi Hook.f. — Maingay's Mahang
Macaranga motleyana Müll.Arg. subsp. griffithiana Whitm.
[syn. Macaranga griffithiana Müll.Arg.]
Macaranga myrmecophila Diels
Macaranga puberula Heine
Macaranga saccifera Pax
Macaranga schweinfurthii Pax
[syn. Macaranga rosea Pax]
Macaranga triloba Müll.Arg. — Common Mahang 


Macaranga chrysotricha K.Schum. & Lauterb.

All parts bear long, stiff, straight, irritant golden hairs (Airy Shaw 1980).



Macaranga hispida Müll.Arg.

This species has irritating brittle hairs on twigs and petioles (von Reis Altschul 1973).



Macaranga thompsonii Merr.
Pengua

Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex.



Mallotus Lour.

Two species are found in tropical Africa and Madagascar. About 140 species are found in eastern and south-eastern Asia and from Indomalaysia to New Caledonia and Fiji, northern and eastern Australia. Mallotus philippinensis Müll.Arg. yields kamala dye.



Mallotus mollissimus Airy Shaw
[syn. Croton mollissimus Geiseler]

The stems are sometimes myrmecophilous below the nodes (Airy Shaw 1980).



Mallotus oppositifolius Müll.Arg.

The fresh leaves are applied as a styptic (Dalziel 1937).



Mallotus subulatus Müll.Arg.

The seeds are beaten and used for marking the faces of young persons (Irvine 1961).



Manihot esculenta Crantz
[syns Manihot utilissima Pohl, Jatropha manihot L.]
Cassava

Sweet and bitter cultivars are known (Rogers 1963). This species is cultivated for manoic or cassava meal (Brazilian arrowroot) and tapioca. The poisonous juice is processed to yield an antiseptic, cassareep, used in preserving meat. Goitre, tropical ataxic neuropathy, and tropical amblyopia have been linked to chronic cyanide intoxication caused by eating cassava (Conn 1973, Liener 1980).

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap. The raw roots and leaves are poisonous when ingested (Lewis & Elvin-Lewis 1977). The seed oil is drastically purgative (Watt & Breyer-Brandwijk 1962).



Manihot glaziovii Müll.Arg.
Ceara Rubber

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap.



Mareya micrantha Müll.Arg.
Executioner

The plant is said to have local anaesthetic properties. The common name is derived from its use as an abortifacient (Irvine 1961).



Megistostigma burmanica Airy Shaw
[syns Tragia burmanica Kurz, Tragia involucrata L.]

The plant has a vesicant effect (Pammel 1911). It is a stinging nettle (Airy Shaw 1969, Nadkarni 1976) with effects on the skin similar to those produced by Tragia bicolor Miq. (Chopra & Badhwar 1940, Behl et al. 1966).



Megistostigma cordatum Merr.

Airy Shaw (1969) notes that this species is a stinging nettle.



Megistostigma malaccense Hook.f.
[syn. Sphaerostylis malaccensis Pax & K.Hoffm.]
Climbing Croton, Moon Nettle Tree

This climbing plant (Burkill 1935) possesses stinging hairs and is known to produce skin reactions in Malaya (Kochummen 1972).



Melanolepis multiglandulosa Rchb.f. & Zoll.
[syn. Melanolepis multiglandulosa Rchb.f. & Zoll. var. glabrata Fosberg]
Alom

Souder (1963) listed this species among spurges that can cause an acute dermatitis on contact with their sap.



Mercurialis annua L.
Annual Mercury

Pammel (1911) lists this species as an irritant and cathartic. The leaves eaten as a vegetable have caused poisoning (Lewis & Elvin-Lewis 1977).



Mercurialis perennis L.

This species has irritant and cathartic properties (Pammel 1911).



Ostodes paniculata Blume

A phorbol diester has been isolated from a chloroform extract of the stems and fruits of this species (Handa et al. 1983).



Pachystylidium hirsutum Pax & K.Hoffm.
[syns Tragia hirsuta Blume, Tragia irritans Merr., Tragia gagei Haines, Tragia delpyana Gagnepain]

Pachystilidium hirsutum is a slender climbing herb with stinging hairs (Airy Shaw 1969, Thurston & Lersten 1969). von Reis Altschul (1973) notes that Tragia hirsuta is irritant to the skin.

The genus Pachystilidium Pax & K.Hoffm. is monotypic. The plant is found in peninsular India, Siam, IndoChina, the Philippines and Java.



Pera Mutis

Forty species are found from Mexico to tropical South America and in the West Indies. The genus has been placed in the family Peraceae by some authorities.



Pera ferruginea Müll.Arg.

The root bark yields a napthaquinone, plumbagin, which has vesicant properties (Thomson 1971). See also Plumbaginaceae.



Picrodendron Planch.

One species is found in the West Indies. The genus has been classified in its own family, the Picrodendraceae, by some authorities.



Picrodendron baccatum Krug & Urb.
[syns Juglans baccata L., Picrodendron macrocarpum Britton, Schmidelia macrocarpa A.Rich.]
Blackwood, Jamaica Walnut

The leaves and bark of Picrodendron macrocarpum have rubefacient properties (Roig y Mesa 1945).



Platygyna Merc.
[syn. Platygyne Howard]

Five species are found in Cuba. Many species have been transferred to the genus Tragia L.

Stinging hairs are found in members of this genus (Thurston & Lersten 1969).



Platygyna hexandra Müll.Arg.

The plant is a vine with stinging hairs (von Reis Altschul 1973).



Platygyna pruriens
[syn. Platygyna urens Merc.]
Pringamoza

The plant has stinging hairs (Pardo-Castello 1923, Wimmer 1926).



Reutealis trisperma Airy Shaw
[syns Aleurites trisperma Blanco, Aleurites saponaria Blanco]
Soft Lumbang, Banucalag Nut

If the kernel of the nut is eaten, a burning sensation is experienced in the mouth and throat. The nut oil is said to irritate the skin and cause eruptions, though certainly it does not do so consistently (Burkill 1935). Souder (1963) listed this species among spurges that cause an acute dermatitis on contact with their sap or latex. von Reis & Lipp (1982) recorded a note from an herbarium sample of Aleurites saponaria that the oil from the seeds is somewhat caustic, causing eruptions when applied to the skin.

The genus Reutealis Airy Shaw is monotypic and is found in the Philippine Islands.



Ricinus communis L.
Castor Oil Plant, Palma Christi

The seeds from this plant, known as castor beans, yield the well known castor oil; the residual meal or pomace which is left after extraction of the oil is used as a fertiliser. The pomace contains ricin, a highly toxic protein, and a water-soluble, carbohydrate-free allergenic protein substance. There is great variation in toxicity from plant to plant. The pomace, used in a dry dust state, can produce asthma and urticaria (Brugsch 1960, Wolfromm et al. 1967). These authors reviewed the literature concerning Type I hypersensitivity reactions to the pomace. Anaphylaxis has resulted from biting into a bean (Arnold 1968) and from contact with a crumbled seed from a necklace (Lockey & Dunkelberger 1968). Family members at home can develop Type I hypersensitivity reactions from dust carried on worker's clothing (Zerbst 1944). Panzani (1962) reported cross-sensitivity between bean dust and a mould (Spondylocladium Mart. ex Corda). Topping et al. (1982) reported castor bean allergy, confirmed by RAST experiments, among workers in the felt industry.

According to Wren (1975), the oil expressed from the seeds, used externally, has been recommended for itch, ringworm and cutaneous complaints. He also notes that the Canary Island women have traditionally used the fresh leaves as an application to the breasts in order to increase milk secretion.

At any time of the year, dermatitis results when juice from the leaves or stems gets on the hands or when the beans are held in the hand (Dorsey 1962, Souder 1963, Behl et al. 1966). Crushed castor oil seeds and ricin powder are both severely irritating to the eye (Grant 1974). Workers in the castor oil industry, during pressing and extracting the oil from the seed, have developed severe conjunctivitis, acute dermatitis and eczema, and attacks of bronchial asthma (Watt & Breyer-Brandwijk 1962). The pomace was found to be a contact allergen by Klauder (1962). Dermatological effects apart from urticaria and conjunctivitis appear to be rare (Key 1961). Szegő (1965) observed positive patch test reactions to the leaf in a patch test study of hospitalised patients from an agricultural region. Patch tests carried out using the leaves crushed in a small quantity of normal saline elicited positive reactions in 3 of 15 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978).

Castor oil is said to produce contact dermatitis (Karabow 1927, Coca et al. 1931). Castor oil in lipstick has caused dry, cracking, painful lips (Sai & Nagai 1982, Sai 1983a), apparently from the free ricinoleic acid present in the oil (Sai 1983b). Make-up remover containing the oil has also caused dermatitis (Brandle et al. 1983). Contact dermatitis from castor oil and vitamin B was attributed to pyridine derivatives (Kadlec & Hanslian 1965).

Fischer & Berman (1981) reported contact allergy from sulfonated castor oil; sulfonated castor oil used as a fabric finish for stockings had irritant effects (Schwartz 1934b). Methyl heptine carbonate, a semi-synthetic chemical derived from the beans and used for the production of artificial violet and jasmine odours can produce contact dermatitis (Tulipan 1938, Klarmann 1962).

Two to four seeds poison man, eight usually being fatal. Because of the hard seed coat, poisoning is unlikely unless the seed is chewed (Lewis & Elvin-Lewis 1977).



Sapium P.Browne
Palode la Flecha, Arrow-Wood

About 120 species are found in tropical and subtropical regions and in America south to Patagonia.

Members of this genus are not invariably hazardous. In Mexico, the milky sap is reputed to be harmful and it is reported on good authority that the Indians utilised it for poisoning their arrows. In Salvador, the sap is claimed to be poisonous and blistering in effect if in contact with the skin for which reason the trees are often left standing when the land is cleared. A colloquial name in Salvador is "chile", the common hot pepper, a name used to express the idea of burning or smarting. In Costa Rica, where the sapiums are called "yos", they are not reported poisonous and the same is true in Panama where the name "olivo" is usually applied to the trees. It seems probable that the species of Sapium differ in their properties and that while some may be harmful, others are innocuous (Standley 1927, Dahlgren & Standley 1944).

The seed of certain species, when it has within it a living grub, is occasionally sold as a curiosity known as a "jumping bean" because it hops about, when warmed, as a result of the activities of the grub (Burkill 1935, Watt & Breyer-Brandwijk 1962, Usher 1974).



Sapium appendiculatum Pax & K.Hoffm.

Pennington (1958) and von Reis Altschul (1973) note that the bark is used to poison fish.



Sapium aubletianum Huber

The latex is irritant and the skin of the hands may be made painful and swollen by grasping the fresh leaves (Burkill 1935).



Sapium biloculare Pax
Hierbe de Flecha

North American Indians of southern California claimed that this, their arrow tree, was dangerous and warned travellers that if they fell asleep under it they would wake up blind (Menninger 1967). The bark of young trees has piscicidal activity but must be handled carefully as the milky juice it exudes irritates the hands and eyes (Pennington 1958).



Sapium eglandulosum Ule

This species has been found to be inhabited by stinging ants (Ule 1906).



Sapium glandulosum Morong
[syns Sapium biglandulosum Müll.Arg., Sapium aucuparium Jacq.]

The white latex is caustic (von Reis Altschul 1973). The hollow stems have been found to be inhabited by ants (Wheeler 1942).



Sapium insigne Trimen

The tree yields an acrid, vesicant milky juice (Chopra & Badhwar 1940, Behl et al. 1966, Nadkarni 1976). Pammel (1911) also referred to its irritant properties.

Taylor et al. (1983) reported the presence of an irritant 4-deoxy-16-hydroxyphorbol esters and related compounds in this species.



Sapium japonicum Pax & K.Hoffm.

Ohigashi & Mitsui (1972) and Ohigashi et al. (1972) reported the isolation of a phorbol diester from this species.



Sapium laurocerasum Desf.

von Reis & Lipp (1982) recorded that although the sap of the tree is reputed to be poisonous, one plant collector felt no discomfort when sap touched his own skin but others reported to be subjected to terrible itching when exposed.



Sapium macrocarpum Müll.Arg.

The plant is reputed to be very poisonous to the skin (von Reis Altschul 1973).



Sapium madagascariense Pax
[syn. Conosapium madagascariense Müll.Arg.]

The milky juice of the plant is vesicant to the skin and smoke from the burning of leaves can produce blindness (Watt & Breyer-Brandwijk 1962).



Sapium myrmecophilum Croizat

The specific epithet suggests that the plant harbours ants.



Sapium sebiferum Roxb.
Tallow Tree

The native tallow tree of southern China is now naturalised in many parts of the world. The plant has a waxy covering yielding a tallow-like substance which is used for making candles. The tree yields an acrid vesicant milky juice (Behl et al. 1966).

The leaves have been reported to contain esters of phorbol and 12-deoxyphorbol (Ohigashi et al. 1983, Seip et al. 1983).



Sapium taburu Ule

Ule (1906) recorded that this species was inhabited by stinging ants.



Sebastiania Spreng.

Ninety-five species are found in tropical America and the Atlantic United States. One species is found in tropical West Africa and from India to southern China and Australia. Three species are found in western Malaysia.

In Belize, the plants are known to cause dermatitis (Towers 1978).



Sebastiania obtusifolia Pax & K.Hoffm.

The juice of the plant can cause blindness (von Reis & Lipp 1982).



Sebastiania pringlei S.Watson

The bark of young trees has piscicidal activity but must be handled carefully as the milky juice it exudes irritates the hands and eyes (Pennington 1958, von Reis Altschul 1973).



Sebastiania ramirezii Maury

This species has piscicidal activity (von Reis Altschul 1973).



Sphaerostylis Baill.
[syn. Tragiella Pax & K.Hoffm.]

Eight species are found in tropical East Africa, Madagascar and western Malaysia.

Stinging hairs are known in members of this genus (Thurston & Lersten 1969).



Spirostachys Sond.

Three or four species are found in eastern tropical and southern Africa. Spirostachys africanus Sond. yields "jumping beans" (see Sapium P.Browne) (Watt & Breyer-Brandwijk 1962).



Spirostachys africana Sond.
[syns Excoecaria africana (Sond.) Müll.Arg., Sapium africanum (Sond.) Kuntze, Stillingia africana (Sond.) Baill.]
African Mahogany, African Sandalwood, Cape Sandalwood, Sandalo Africano, Tomboti, Tambootie

The sap of the tree is reportedly acrid and capable of causing serious inflammation if applied to the eye or to skin abrasions. It may blister tender skin. The African is warned against the tambootie tree from earliest youth. The sawdust is very dangerous, irritating the eyes of sawyers, and may even cause blindness (Codd 1951, Pardy 1954, Watt & Breyer-Brandwijk 1962).

The wood is extremely handsome and makes attractive furniture. It is exported from East Africa as a substitute for sandalwood (Davy 1929). The wood is unsuitable for ox-yokes since it produces a "burning" effect on the animals' necks. Necklaces and charms, however, are made of it locally (Watt & Breyer-Brandwijk 1962).

Schmidt RJ & Olivier GW (1984 — unpublished observation) found extracts of the leaves and bark of this species to be non-irritant in the mouse ear irritancy assay.



Stillingia sylvatica L.
Queen's Root, Queen's Delight, Yaw Root

The juice of the green root is acrid; it inflames and swells the hands (Dispensatory 1884, White 1887) producing smarting and irritation (Piffard 1881).

Adolf & Hecker (1980) reported the presence of several tigliane and daphnane polyol esters in the roots of this species.



Stillingia texana I.M.Johnst.
[syn. Stillingia linearifolia Small]
Queen's Delight

The milky sap is said to cause skin blisters, and is used to cure ringworm (von Reis Altschul 1973).



Synadenium cupulare Wheeler
[syn. Euphorbia cupularis Boiss.]

Application of the latex to the eye causes pain, severe inflammation, and even loss of the eye. On the skin, the latex produces an itchy rash, followed by blisters, sores, and desquamation. The latex gives off a highly irritant vapour; when collecting the plant, even if the specimen is held at arm's length, irritation of the eyelids, nostrils, and lips may be felt for several hours (Watt & Breyer-Brandwijk 1962).



Synadenium grantii Hook.f.
African Milk Bush

The plant is widely grown as an ornamental plant in the tropics and under glass in colder regions. The latex is undoubtedly extremely irritant (Watt & Breyer-Brandwijk 1962, Everist 1972) and was used by the Masai people of southern Africa as a blistering remedy for East Coast fever, the application being made over the swollen glands (Mettam 1932).

A gardener noted that the latex dripped from the cut stems onto the arms and forearms. She experienced no immediate discomfort but four hours later a burning sensation was felt and eight hours after exposure, streaky erythema and blisters appeared. Application of a drop of latex to the forearm of a volunteer was followed, after 6 hours, by intense irritation then by blistering (Rook 1965).

Thorold (1953) described the sudden development in 33 steers of large oedematous swellings between the brisket and near fore leg. Some also showed lesions between the hind limbs. No animal showed a lesion on the offside. Eight steers died. He believed that the lesions may have been caused maliciously using the latex of Synadenium grantii, a plant common in the nearby countryside.

Kinghorn (1980) identified 12-O-tigloyl-4-deoxyphorbol-13-isobutyrate as a major skin irritant principle in the latex of Synadenium grantii.



Synadenium kirkii N.E.Br.

The plant is regarded as poisonous, the latex apparently being irritant (Watt & Breyer-Brandwijk 1962).



Tragia L.

One hundred species are found in tropical and subtropical regions.

Pammel (1911), Wimmer (1926), Hutchinson & Dalziel (1928), Standley (1930), von Reis Altschul (1973), and Morton (1981) refer to the stinging hairs of:

Tragia akwapimensis Prain
Tragia angustifolia Benth.
Tragia benthamii Baker
Tragia chevalieri Beille
Tragia laminularis Müll.Arg.
Tragia miqueliana Müll.Arg.
Tragia nepetaefolia Cav.
Tragia polygonoides Prain
Tragia pungens Müll.Arg.
[syn. Jatropha pungens Forssk.]
Tragia senegalensis Müll.Arg.
Tragia spathulata Benth.
Tragia tenuifolia Benth.
Tragia urens L.
Tragia urticaefolia Michx.
Tragia wildemanii Beille
Tragia yucatanensis Millsp. 

This list could no doubt be expanded to include other species in the genus. Tragia preussii Pax, however, does not bear stinging hairs (Hutchinson & Dalziel 1928).



Tragia adenanthera Baill.

Handling the plant results in immediate irritation of the skin (Watt & Breyer-Brandwijk 1962).



Tragia affinis Müll.Arg.

This species is armed with stinging hairs (Anon 1912).



Tragia bicolor Miq.
Noseburn

The stinging hairs which cover the entire plant have sharp silicaceous points which break off when touched and penetrate the skin. In addition to mechanical injury, sharp burning pain and inflammation occurs, like the effects produced by nettles (Urtica L. species, fam. Urticaceae) (Behl et al. 1966).



Tragia cannabina L.f.

Rao & Sandararaj (1951) described the stinging hairs of this species. The plant has effects similar to those of Tragia bicolor Miq. (Behl et al. 1966). Hutchinson & Dalziel (1928) note that Tragia cannabina var. intermedia Prain is beset with stinging hairs.



Tragia cissoides Müll.Arg.

Rao & Sandararaj (1951) noted that the stinging hairs of this species were morphologically dissimilar to those of Tragia cannabina L.f.



Tragia cordifolia Vahl

The plant has a vesicant action (Pammel 1911).



Tragia hispida Willd.

The plant has stinging hairs (von Reis Altschul 1973). The effects are similar to those of Tragia bicolor Miq. (Behl et al. 1966).



Tragia rupestris Sond.

Rubbing the leaf on the forehead has been used in southern Africa for the relief of headache. Apparently, the application stings (Watt & Breyer-Brandwijk 1962).



Tragia volubilis L.
Vine Nettle, Twining Cowitch, Creeping Cowitch

Pammel (1911) lists the species as being irritant. The plant bears stinging hairs (Hutchinson & Dalziel 1928, Thurston & Lersten 1969) which sting severely (von Reis Altschul 1973). Cook & Collins (1903) noted that contact with the plant causes instant stinging and burning sensations, and may result in blisters.



Vernicia fordii (Hemsl.) Airy Shaw
[syn. Aleurites fordii Hemsl.]
Tung Oil Tree, China Wood-Oil Tree, Kalo Nut

The tree is cultivated for tung oil contained in the seeds. The oil may be used in varnishes, and paints. Contact with tung oil can produce skin ulcers (Anon 1934), dermatitis of the groin and face, or generalised dermatitis (Tupholme 1939). According to Swaney (1938), finished tung oil varnishes are innocuous, but the vapour of heated tung oil can produce allergic contact dermatitis. A small proportion of workers handling the oil, and then probably only the heated oil, develop an allergic reaction to it (Watt & Breyer-Brandwijk 1962).

The liquid extruded by incision of the fruit exerts a local irritant effect on the skin (Carratalá 1936). Chewing a portion of the kernel and spitting it out produces irritation of the mouth and lips which continues for several hours (Watt & Breyer-Brandwijk 1962). The seeds and other plant parts are poisonous to man when ingested (Lewis & Elvin-Lewis 1977).

Chronic poisoning in animals from ingestion of Vernicia fordii produces, as part of the syndrome, cracking of the skin of the muzzle (Oakes & Butcher 1962).

The fruits have been found to contain esters of 16-hydroxyphorbol and 4-deoxy-16-hydroxyphorbol (Okuda et al. 1974, Okuda et al. 1975, Hirota et al. 1979).



Victorinia regina (Léon) Léon
[syn. Jatropha regina Léon]

The plant, which is found in Cuba, contains an abundant irritant latex (von Reis & Lipp 1982).


References

  • Adolf W, Hecker E (1977) Diterpenoid irritants and cocarcinogens in Euphorbiaceae and Thymelaeaceae: structural relationships in view of their biogenesis. Israel Journal of Chemistry 16(1): 75-83 [doi] [url] [url-2]
  • Allen PH (1943) Poisonous and injurious plants of Panama. American Journal of Tropical Medicine 23(Suppl): 3-76 [doi] [url] [url-2]
  • Anon (1893) Caper spurge. - a poisonous plant. Agricultural Gazette of New South Wales 4(3): 215
  • Aplin TEH (1966) Poison plants in the garden. Journal of Agriculture of Western Australia 7(1): 23-27
  • Arnold HL (1968) Poisonous Plants of Hawaii. Rutland, VT: Charles E. Tuttle Company [WorldCat] [url]
  • Barrett MF (1956) Common Exotic Trees of South Florida. Gainesville: University of Florida Press
  • Behl PN, Captain RM, Bedi BMS, Gupta S (1966) Skin-Irritant and Sensitizing Plants Found in India. New Delhi: PN Behl [WorldCat]
  • Bhalme AY, Pasricha JS (1986) Irritant and sensitizing potential of some common Indian cacti, succulents, lichens and aquatic plants. Indian Journal of Dermatology, Venereology and Leprology 52(2): 89-93 [url] [url-2] [pmid]
  • Chopra IC, Abrol BK, Handa KL (1960) Part One. With particular reference to the botanical aspects. In: Arid Zone Research — XIII. Medicinal Plants of the Arid Zones, pp. 11-53. Paris: United Nations Educational, Scientific and Cultural Organization [WorldCat] [url]
  • Chopra RN, Badhwar RL (1940) Poisonous plants of India. Indian Journal of Agricultural Science 10(1): 1-44
  • Cleland JB (1914) Plants, including fungi, poisonous or otherwise injurious to man in Australia. Australasian Medical Gazette 35(25; 26): 541-544; 569-572 [url]
  • Cleland JB, Lee DJ (1963) The poisonous and urticating plants of Australia. In: Keegan HL, Macfarlane WV (Eds) Venomous and Poisonous Animals and Noxious Plants of the Pacific Region, pp. 3-14. Oxford: Pergamon Press [WorldCat] [url]
  • Coca AF, Walzer M, Thommen AA (1931) Asthma and Hayfever in Theory and in Practice. Springfield, Ill.: Charles C Thomas
  • Codd LEW (1951) Trees and Shrubs of the Kruger National Park. Union of South Africa, Department of Agriculture, Division of Botany and Plant Pathology. Botanical Survey Memoir No. 26. Pretoria: Government Printer [WorldCat]
  • Conn BJ, Damas KQ (2005b) PNGTreesKey — Endospermum medullosum L.S.Sm. [online article]: http://www.pngplants.org/PNGtrees/TreeDescriptions/Endospermum_medullosum_L_S_Sm.html; accessed June 2011 [url]
  • Dahlgren BE, Standley PC (1944) Edible and Poisonous Plants of the Caribbean Region. Washington, DC: United States Government Printing Office [doi] [WorldCat] [url] [url-2]
  • Dao L (1967) Dermatitis por plantas en los llanos de Venezuela. [Dermatitis from plants in the plains of Venezuela]. Dermatologia Internationalis 6(2): 77-81 [doi] [url] [url-2] [pmid]
  • Díaz JL (1976) Usos de las Plantas Medicinales de México. México: Instituto Mexicano para el Estudio de las Plantas Medicinales [WorldCat]
  • Dorsey CS (1962) Plant dermatitis in California. California Medicine 96(6): 412-413 [url] [url-2] [pmid]
  • Duke-Elder S, MacFaul PA (1972b) System of Ophthalmology, Vol. XIV. Injuries Part 2. Non-Mechanical Injuries. London: Henry Kimpton [WorldCat]
  • Evans FJ, Kinghorn AD (1977) A comparative phytochemical study of the diterpenes of some species of the genera Euphorbia and Elaeophorbia (Euphorbiaceae). Botanical Journal of the Linnean Society 74(1): 23-35 [doi] [url] [url-2]
  • Evans FJ, Schmidt RJ (1976) Two new toxins from the latex of Euphorbia poisonii. Phytochemistry 15(2): 333-335 [doi] [url]
  • Francis DF, Southcott RV (1967) Plants Harmful to Man in Australia. Miscellaneous Bulletin No. 1, Botanic Garden Adelaide [WorldCat] [url]
  • Gardner CA, Bennetts HW (1956) The Toxic Plants of Western Australia. Perth: West Australian Newspapers [WorldCat]
  • Gerarde J (1636) The Herball or Generall Historie of Plantes. Very much enlarged and amended by Thomas Johnson citizen and apothecarye of London, 2nd edn. London: A Islip, J Norton and R Whitakers [WorldCat] [url] [url-2]
  • González de la Rosa M (1976) Un antídoto natural para la causticación ocular por látex de euforbias. [A natural antidote for ocular caustication by latex of Euphorbia]. Archivos de la Sociedad Canaria de Oftalmología (1): 84-88 [url] [url-2]
  • Greshoff M (1909) Phytochemical investigations at Kew. Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew) (10): 397-418 [doi] [url]
  • Hamilton W (1846) On the properties of the Hippomane mancinella, or manchineel tree. Pharmaceutical Journal and Transactions 5(9): 408-412 [url] [url-2]
  • Hausen BM (1981a) Woods Injurious to Human Health. A manual. Berlin: Walter de Gruyter [WorldCat]
  • Hyde MA, Wursten BT, Ballings P, Coates Palgrave M (2022) Flora of Zimbabwe: Jatropha curcas L. [online article]: https://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=135390 ; accessed July 2022 [url]
  • Karabow AS (1927) [An occupational affection of the skin in workers preparing castor oil]. Moskovskii Meditsinskii Zhurnal 7: 47
  • Kinghorn AD, Evans FJ (1975) A biological screen of selected species of the genus Euphorbia for skin irritant effects. Planta Medica 28(4): 325-335 [doi] [url] [url-2]
  • Kinghorn AD (1980) Major skin-irritant principle from Synadenium grantii. Journal of Pharmaceutical Sciences 69(12): 1446-1447 [doi] [url] [url-2] [pmid]
  • Klauder JV (1962) Actual causes of certain occupational dermatoses. Archives of Dermatology 85: 441
  • Lewin L, Guillery H (1913) Die Wirkungen von Arzneimitteln und Giften auf das Auge. [The Effects of Medicaments and Poisons on the Eye], 2nd edn, Vol. 2. Berlin: August Hirschwald [WorldCat] [url] [url-2]
  • Lewis WH, Elvin-Lewis MPF (1977) Medical Botany. Plants affecting man's health. New York: John Wiley [WorldCat]
  • Li X-L, Li Y, Wang S-F, Zhao Y-L, Liu K-C, Wang X-M, Yang Y-P (2009) Ingol and ingenol diterpenes from the aerial parts of Euphorbia royleana and their antiangiogenic activities. Journal of Natural Products 72(6): 1001-1005 [doi] [url] [url-2] [pmid]
  • Lipparoni E (1951) Dermatiti da zecche e dermatiti da sostanze vegetali. Note ed osservazioni circa taluni casi riscontrati in Somalia. [Tick dermatoses and dermatoses caused by plant materials. Notes and observations on some cases occurring in Somalia]. Archivio Italiano di Scienze Mediche Tropicali e di Parassitologia 32(9): 913-922
  • Lockey SD, Dunkelberger L (1968) Anaphylaxis from an Indian necklace. Journal of the American Medical Association 206: 2900
  • Loudon JC, Loudon JW, Don G, Wooster D (1855) Loudon's Encyclopædia of Plants : comprising the specific character, description, culture, history, application in the arts, and every other desirable particular respecting all the plants indigenous to, cultivated in, or introduced to Britain. London: Longman, Brown, Green, and Longmans [WorldCat]
  • Maiden JH (1909b) On some plants which cause inflammation or irritation of the skin. Part II. Agricultural Gazette of New South Wales 20(12): 1073-1082 [url] [url-2]
  • Maiden JH (1917) Weeds of New South Wales. Agricultural Gazette of New South Wales 28(2): 131-133 [url] [url-2]
  • Menninger EA (1967) Fantastic Trees. New York: Viking Press [WorldCat] [url]
  • Morton JF (1958) Ornamental plants with poisonous properties. Proceedings of the Florida State Horticultural Society 71: 372-380 [url] [url-2]
  • Morton JF (1962a) Ornamental plants with toxic and/or irritant properties. II. Proceedings of the Florida State Horticultural Society 75: 484-491 [url] [url-2]
  • Morton JF (1964) Honeybee plants of South Florida. Proceedings of the Florida State Horticultural Society 77: 415-436 [url] [url-2]
  • Opferkuch HJ, Hecker E (1974) New diterpenoid irritants from Euphorbia ingens. Tetrahedron Letters 15(3): 261-264 [doi] [url]
  • Pammel LH (1911) A Manual of Poisonous Plants. Chiefly of North America, with Brief Notes on Economic and Medicinal Plants, and Numerous Illustrations. Cedar Rapids, IA: Torch Press [WorldCat] [url] [url-2]
  • Pardy AA (1954) Notes on indigenous trees and shrubs of Southern Rhodesia. Rhodesia Agricultural Journal 51: 489-492
  • Perrot E and Paris R (1971) Les Plantes Medicinales. Vol. 1 & 2. Paris: Presses Universitaires Paris.
  • Pope WT (1968) Manual of Wayside Plants of Hawaii. Rutland, Vermont: Charles E. Tuttle Co.
  • Raymond WD (1939) Native poisons and native medicines of Tanganyika. Journal of Tropical Medicine and Hygiene 42(19): 295-303 [url]
  • Rickson FR (1980) Developmental anatomy and ultrastructure of the ant-food bodies (Beccariian bodies) of Macaranga triloba and M. hypoleuca (Euphorbiaceae). American Journal of Botany 67(3): 285-292 [doi] [url] [url-2]
  • Rizk AM, Hammouda FM, El-Missiry MM, Radwan HM, Evans FJ (1984) Macrocyclic diterpene esters from Euphorbia royleana. Phytochemistry 23(10): 2377-2379 [doi] [url]
  • Schwartz L (1934b) The actual causes of dermatitis attributed to socks. Public Health Reports 49(40; Oct 5): 1176-1185 [url] [url-2]
  • Singh R, Siddiqui MA, Baruah MC (1978) Plant dermatitis in Delhi. Indian Journal of Medical Research 68(Oct): 650-655 [url] [pmid]
  • Sofat BK, Sood GC, Chandel RD, Mehrota SK (1972) Euphorbia royleana latex keratitis. American Journal of Ophthalmology 74(4): 634-637 [doi] [url] [url-2] [pmid]
  • Sood GC, Sofat BK, Chandel RD (1971) Injury to the eye by the sap of Euphorbia royleana. British Journal of Ophthalmology 55(12): 856-857 [doi] [url] [url-2] [pmid]
  • Souder P (1963) Poisonous plants on Guam. In: Keegan HL, Macfarlane WV (Eds) Venomous and Poisonous Animals and Noxious Plants of the Pacific Region, pp. 15-29. New York: Pergamon Press [WorldCat] [url]
  • Standley PC (1937b) Flora of Costa Rica, Part II. Publications of the Field Museum of Natural History, Botanical Series 18: 398-780+ix [url] [url-2]
  • Stuppy W, van Welzen PC, Klinratana P, Posa MCT (1999) Revision of the genera Aleurites, Reutealis and Vernicia (Euphorbiaceae). Blumea: Biodiversity, Evolution and Biogeography of Plants 44(1): 73-98 [url] [url-2]
  • Szegő L (1965) Sensibilisation durch Landwirtschaftliche Pflanzen und Pflanzenschutzmitteln I. Untersuchungen mit Pflanzen-(Blatt-)Extrakten [Sensitisation by agricultural crops and crop-protection preparations I. Studies of plant (leaf) extracts]. Acta Medica Academiae Scientiarum Hungaricae 21(1): 19-24 [url] [url-2]
  • Thomson RH (1971) Naturally Occurring Quinones, 2nd edn. London: Academic Press [doi] [WorldCat] [url]
  • Thorold PW (1953) Suspected malicious poisoning. Journal of the South African Veterinary Medical Association 24(4): 215-217
  • Touton K (1932) Hauterkrankungen durch phanerogamische Pflanzen und ihre Produkte (Toxicodermia et Allergodermia phytogenes) [Skin Diseases Caused by Phanerogamic Plants and their Products (Toxicodermia et Allergodermia phytogenes)]. In: Jadassohn J (Ed.) Handbuch der Haut- und Geschlechtskrankheiten. Band IV, Teil I. Angeborene Anomalien. Lichtdermatosen. Pflanzengifte. Thermische Schädigungen. Einfluss Innerer Störungen auf die Haut [Handbook of Skin and Venereal Diseases. Volume IV, Part I. Congenital abnormalities. Photodermatoses. Plant toxins. Thermal injuries. Influence of internal disorders on the skin], pp. 487-697. Berlin: Julius Springer [doi] [WorldCat] [url] [url-2]
  • Upadhyay RR, Hecker E (1976) A new cryptic irritant and cocarcinogen from seeds of Croton sparciflorus. Phytochemistry 15(6): 1070-1072 [doi] [url]
  • Upadhyay RR, Islampanah S, Davoodi A (1980) Presence of a tumor-promoting factor in honey. Gann – Japanese Journal of Cancer Research 71(4): 557-559 [doi] [url] [url-2]
  • Uphof JCT (1959) Dictionary of Economic Plants. New York: Hafner Publishing Company [WorldCat]
  • Van Hasselt AWM, Henkel JB (1862) Handbuch der Giftlehre für Chemiker, Ärzte, Apotheker und Gerichtspersonen [Handbook of Toxicology for Chemists, Doctors, Pharmacists and Court Officials], Vol. 1, Allgemeine Giftlehre und die Gifte des Pflanzenreichs [General Toxicology and the Poisons of the Plant Kingdom]. Braunschweig: Friedrich Vieweg und Sohn [WorldCat] [url] [url-2]
  • Watt JM, Breyer-Brandwijk MG (1962) The Medicinal and Poisonous Plants of Southern and Eastern Africa. Being an account of their medicinal and other uses, chemical composition, pharmacological effects and toxicology in man and animal, 2nd edn. Edinburgh: E & S Livingstone [doi] [WorldCat] [url] [url-2]
  • Wimmer C (1926) Morphologisches über Pflanzen und Tiere, welche Hautschädigungen hervorrufen. [Morphology of plants and animals that cause skin damage]. In: Ullmann K, Oppenheim M, Rille JH (Eds) Die Schädigungen der Haut durch Beruf und gewerbliche Arbeit, Vol. 2, pp. 485-508. Leipzig: Leopold Voss [WorldCat] [url]
  • Wren RC (1975) Potter's New Cyclopaedia of Botanical Drugs and Preparations. (Re-edited and enlarged by Wren RW). Bradford, Devon: Health Science Press [WorldCat] [doi] [url] [url-2]
  • [Others yet to be added]



Richard J. Schmidt

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