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(Soapberry family)


2000 species in 150 genera are found in tropical and subtropical regions. Litchi chinensis furnishes edible fruit (litchi).

Acer palmatum Thunb. and other species are often planted as ornamental trees and shrubs. They are also popular as subjects for bonsai, a natural art form produced by artificially stunting the growth of the specimen.

Many species of Acer yield good timber. Acer saccharum Marshall and other species in eastern North America yield maple syrup.

The pollens of the anemophilous species, less commonly the amphiphilous and entomophilous species, are minor causes of pollinosis (Wodehouse 1971). Inhalation of fungal particles from maple bark (Acer L. spp.) can cause maple bark disease, a form of allergic alveolitis (Seaton & Morgan 1984).

[Summary yet to be added]

Acer L.

Species of Acer L., Tilia L. (fam. Tiliaceae), and certain other deciduous trees may become heavily infested with aphids living on the undersides of the leaves. Whilst feeding, these insects excrete a sugary liquid known as honeydew which falls from the trees as a fine rain. Large numbers of aphids may also fall from the trees. A case has been described where an elderly woman with suspected delusions of parasitosis (Ekbom syndrome; delusional infestation) who, after unknowingly sitting under a species of Acer during the summer months, complained of a sticky feeling and a crawling sensation caused by green insects on her skin (Mitchell 1975).

Maple is said to be a sensitising wood by Weber (1953), repeated by McCord (1958).

Acer macrophyllum Pursh
Big-Leaf Maple, Oregon Maple, Oregon-Ahorn

The fruits (maple keys) are covered with spiny hairs that can penetrate and irritate the skin (Hebda 2003).

Acer maximowiczianum Miq.
[syns Acer nikoense Delendick, Acer nikoense Maxim., Crula nikoense (Maxim.) Nieuwl.]
Nikko Maple

An arylbutanoid known as 4-([3S]-3-hydroxybutyl)phenol, or as 4-(4-hydroxyphenyl)-2-butanol, 4HPB, frambinol, raspberry alcohol, betuligenol, or rhododenol (or, more correctly, rhododendrol) is found naturally in this species (Inoue et al. 1978, Das et al. 1993). Rhododenol is a good substrate for tyrosinase. Cosmetic products containing rhododenol induce tyrosinase activity-dependent cytotoxicity in melanocytes in the epidermis at application sites, resulting in decreased melanin production. Although intended only to produce a paler skin tone, many users have developed white blotches on the skin: rhododenol-induced leukoderma (Kasamatsu et al. 2014, Sasaki et al. 2014, Nishigori et al. 2015). Both R-(−) and S-(+) enantiomers of rhododendrol exhibit this activity (Ito et al. 2014). Because of this adverse effect, proprietary skin-lightening products containing rhododendrol [CAS RN 69617-84-1]a have been withdrawn from the market, and users advised against their use.b,c

Rhododendrol is also found in certain species of Rhododendron L., fam. Ericaceae (Archangelsky 1901, Das et al. 1993) and Betula L., fam. Betulaceae (Santamour & Vettel 1978, Santamour & Lundgren 1997).


Acer Nikoense Bark Extract & Acer Nikoense Branch/Stem Extract [INCI; of uncertain composition (see Schmidt 2017)] are recognised cosmetic product ingredients purported to have skin conditioning properties (Standing Committee on Cosmetic Products 2019, CosIng 2023/4).

Acer negundo L.
[syn. Negundo aceroides Moench]
Ashleaf Maple, Box Elder Maple, Eschen-Ahorn

The pollen of this and another species of maple has been implicated as a cause of airborne contact dermatitis by Lovell et al. (1955) who observed positive patch test reactions to "box elder pollen oil" and to "maple pollen oil" in two patients.

Acer pictum Thunb.
Painted Maple

Nadkarni (1976) states that the leaves of this species are irritant.

Acer platanoides L.
Norway Maple, Spitzahorn

The wood was listed as irritant by Hanslian & Kadlec (1966), probably from Weber (1953).

Acer rubrum L.
Red Maple, Swamp Maple, Roter Ahorn

An extract of the bark has been used for its astringent effect in the treatment of sore eyes by North American Indians (Wren 1975).

[Further information available but not yet included in database]

Acer saccharum Marshall
Sugar Maple, Zucker-Ahorn

This species has been found to contain 2,6-dimethoxy-1,4-benzoquinone, a known contact allergen (Hausen 1978a).


[Further information available but not yet included in database]

Aesculus flava Sol. ex Hope
[syns Aesculus flava Aiton, Aesculus octandra Marshall]
Sweet Buckeye, Yellow Buckeye, Appalachen-Rosskastanie

The flowers and young shoots of some species of Aesculus L., especially Aesculus octandra, are said to be capable of causing contact dermatitis (Massey 1941).

Aesculus hippocastanum L.
[syn. Hippocastanum vulgare Gaertn.]
Horse Chestnut, Oblionker Tree

A particle of the shell of the horse chestnut became embedded in the conjunctiva and caused necrosis and ulceration by a local toxic effect (Grant 1974).

Cardiospermum halicacabum L.
[syns Cardiospermum luridum Blume, Corindum halicacabum (L.) Medik.]
Black Winter Cherry, Blister Creeper, Balloon Vine, Heart Pea, Ballonpflanze

The leaves is irritant and are used for rubefacient purposes (Quisumbing 1951, Gardner & Bennetts 1956, Watt & Breyer-Brandwijk 1962, Behl et al. 1966). Gardner & Bennetts (1956) also note that the root has been used in the treatment of haemorrhoids, probably from Webb (1948a).

Deinbollia oblongifolia (E.Mey. ex Arn.) Radlk.
[syns Sapindus capensis Hochst., Sapindus oblongifolius (E.Mey. ex Arn.) Sond., Rhus oblongifolia E.Mey. ex Arn.]
Dune Soapberry

A foam is produced by shaking the berries from Sapindus oblongifolius with water (Watt & Breyer-Brandwijk 1962).

Hippobromus pauciflorus (L.f.) Radlk.
[syns Hippobromus alata Eckl. & Zeyh., Rhus alata Thunb., Rhus pauciflora L.f.]
Bastard Horsewood, False Horsewood

A decoction of the plant is used in southern Africa as a sternutatory. Frothing of the roots, when mixed with water, may indicate the presence of saponins (Watt & Breyer-Brandwijk 1962).

The genus is monotypic.

Melicoccus bijugatus Jacq.
[syns Melicocca bijuga L., Melicocca carpoodea Juss.]
Genipe, Honey-Berry, Mamoncillo, Spanish Lime

This species which provides timber and edible fruit was reported to cause contact dermatitis by Pardo Costello & Reaud (1941).

Paullinia cupana Kunth
[syn. Paullinia sorbilis Mart.]

The fruit of this climbing shrub provides an edible seed rich in caffeine. It was formerly officinal (Remington et al. 1918, Todd 1967).

Piffard (1881), citing an earlier report by Montegazza, noted that ingestion of guarana [seed ?] has been reported to cause urticaria and pruritus.

Paullinia Cupana Fruit Extract / Fruit Powder / Seed Extract / Seed Powder / & Seed Water [INCI; CAS RN 84929-28-2; of uncertain composition (see Schmidt 2017)]a, are recognised cosmetic product ingredients variously purported to have skin conditioning, astringent, tonic, and/or emollient properties, as is also Caffeine [INCI; CAS RN 58-08-2; masking & skin conditioning] (Standing Committee on Cosmetic Products 2019, CosIng 2023/4). According to Baumann (2007), caffeine is well known to cause dehydration of fat cells, temporarily improving the appearance of cellulite and is a common additive to cellulite treatment products.

Koo et al. (2007) reported that topical application of caffeine after UV exposure decreases UV-induced skin roughness and transverse rhytids in SKH-1 hairless mice.

Paullinia pinnata L.
[syns Paullinia angusta N.E.Br., Paullinia hostmannii Steud., Paullinia pendulifolia Rusby]
Barbasco, Bejuco de Costillo, Bread and Cheese Plant, Sweet Gum, Paullinie

The root and root bark are applied for rubefacient purposes (Watt & Breyer-Brandwijk 1962).

Sapindus drummondii Hook. & Arn.
[syns Sapindus saponaria subsp. drummondii (Hook. & Arn.) A.E.Murray, Sapindus saponaria var. drummondii (Hook. & Arn.) L.D.Benson]
Jaboncillo, Western Soapberry

Dermatitis can result from handling of the fruits (Schwartz et al. 1957).

Sapindus mukorossi Gaertn.
[syns Sapindus detergens Roxb., Sapindus indicus Poir, Sapindus utilis Trab.]
Chinese Soapberry

In traditional Chinese medicine, this species provides the crude drug Fructus/Semen Sapindi Mukorossi or Chinese Soapberry Fruit/Seed (wu huan zi; 无患子).a According to Stuart (1911) the globular fruit outside the seed is used in traditional Chinese medicine under the name of 木患肉 (mu huan rou). It is considered to be slightly poisonous, and is cleansing to the skin, removing tan and freckles. Behl et al. (1966) noted that the pulp of the fruit forms a lather with water and may be used as a shampoo.

[Further information available but not yet included in database]

Sapindus saponaria L. var. saponaria
[syn. Sapindus marginatus Willd.]
False Dogwood, Jaboncillo, Soap-Nut Tree, Southern Soapberry, Wingleaf Soapberry

The berries form a lather with water and may be used as soap. They contain saponins that may cause a severe skin rash in sensitive individuals (Allen 1943, Blohm 1962, Morton 1962a).

[Further information available but not yet included in database]

Schleichera oleosa (Lour.) Oken
[syns Melicocca trijuga (Willd.) Juss., Pistacia oleosa Lour., Schleichera trijuga Willd.]
Ceylon Oak, Kussum, Paka, Zeepboom

Shellac is a resinous excretion of an insect which sucks the juices of this and other trees (Hicks 1961). This tree yields Mirzapore lac and also, useful timber, edible seed and seed oil. Macassar oil (kusum oil) is derived from the seed kernels (Budavari 1996). Macassar oil is also a name for ylang-ylang oil from Cananga. Macassar oil may contain additives such as safflower oil from Carthamus tinctorius L., (fam. Compositae). Harry (1948) referred to two papers concerning dermatitis or allergy from the oil but considered it innocuous. Shellac is said to have irritant or sensitising properties (Greenberg and Lester 1954) and has been removed from certain brand-name cosmetics (Anon 1973). Hausen (1970) refers to Wehmer (1929) and Anon (1940) for injurious effects of the plant products. The oil of macassar wood, possibly of this species, caused dermatitis in a planer (Buschke and Joseph 1927). Shellac is noted under Acer.

The genus is monotypic.

[Further information available but not yet included in database]


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Richard J. Schmidt

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