Generally known as sedges, perhaps 4000 species in 90 genera have been described from all parts of the world.
Certain members of this family are noted for the readiness with which the edges of their leaves can cause lacerations of the skin.
This species has been found to be a hyperaccumulator of cobalt when growing on soils rich in this element. Brooks et al. (1980) reported a cobalt content of 4200 ppm in dried plant material. The sensitising properties of cobalt and its salts are well documented (Cronin 1980, Malten et al. 1976).
Between 1500 and 2000 species are of cosmopolitan distribution, being especially common in wet and marshy locations in temperate regions.
The leaves, which have fine sawing and cutting edges, made harder by the presence of silica in the superficial cells, can cause mechanical irritation of the hands of basket weavers and persons in allied occupations (Schwartz et al. 1957).
Howes (1974) notes that members of this genus in New Zealand are liable to cut the hands.
The large prickly heads of a plant thought to be this species are injurious to the feet (Turner & Bell 1971).
Wimmer (1926) refers to the silicaceous saw-tooth like edges of the leaves of this species as a possible cause of mechanical injury.
Between 50 and 60 species are found in tropical and temperate regions especially in Australia; one species is of almost cosmopolitan distribution.
Stinging ants have been reported to inhabit the hollow stems of this species (Wheeler 1942).
This and related sedges have long knife-like leaves armed with small sharp teeth.
About 550 species are found in tropical and warm temperate regions.
Cyperus papyrus L. provided the well known papyrus of Egypt which afforded the Ancient Egyptians the compressed pith upon which they wrote their records. The stem was split into thin strips, which were pressed together while still wet (Burkill 1935).
The dried stems are made into rush mats; several persons who cultivated the plant developed contact dermatitis (Eun 1984).
The juice is irritant to the skin (Watt & Breyer-Brandwijk 1962).
In NW Moroccan traditional medicine, stem galls from this plant mixed with henna leaves (Lawsonia inermis L., fam. Lythraceae) are powdered and kneaded with water to make a hair tonic for external application (Merzouki et al. 2000).
Patch tests carried out using the leaves of this species crushed in a small quantity of normal saline elicited no positive reactions in 17 contact dermatitis patients tested in New Delhi, India (Singh et al. 1978).
Forty species are native to China, Malaysia, Australia, and eastwards to Polynesia and Hawaii.
Cleland (1925) thought that it was this species that possessed leaf edges capable of producing deep cuts in the skin.
This species was incriminated in a case of Oppenheim's meadow dermatitis as the cause of photosensitivity (Mariconda 1936).
These plants should not be confused with Typha latifolia L. (fam. Typhaceae), which is commonly known as the great reedmace or bulrush.
The plant is used to make chair seats and mats. Dermatitis from reed matting derived from bulrushes was probably due to the reed bug Chilactis (Szegö & Balogh 1965).
The spiny leaves (Howes 1974) are capable of producing mechanical injury.
Some 200 species are found in tropical and sub-tropical regions.
Howes (1974) notes that West Indian species of this genus are liable to cut the hands. von Reis & Lipp (1982) recorded a note from an herbarium specimen of an unidentified Scleria species that the sharp edges could cut the skin of animals and man.
The rough edges of the leaves inflict painful cuts and scratches on any exposed surface of the skin (Allen 1943).
The leaves are rough and are used for polishing wood (Burkill 1935).
The edges of the leaves may cut the skin like knives (Allen 1943).
The achenes terminate in hooked bristles which adhere closely to clothing and penetrate the skin (Standley 1937).