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(Pea or Bean family)
One species, found in tropical east Africa, Madagascar and Mauritius, yields copal resin, which is dug up from the soil near the roots or in a half-fossilised condition from places where trees once existed.
Copal is derived from this tree and from Hymenaea courbaril, Leguminosae. Copal is known as resin copal, gum copal, animé (soft copal), kaurie or cowrie and occurs as hard or soft copal (Budavari 1996).
Hypersensitivity has been reported and dermatitis occurs in its use in manufacture (Greenberg and Lester 1954, Ferrand et al. 1937, Schwartz et al. 1957).
- Trachylopium hornemannianum
This species furnishes a copal resin which is dug from the remains of trees long dead. A variety of plants yield copals e.g. Agathis, Bursera, Canarium, Copaifera, and Hymenaea (Usher 1954).
Contact sensitivity to copal has been reported (Ferrand et al. 1937) and dermatitis can occur in workers in its manufacture (Schwartz et al. 1947).
- Trifolium L.
- Clover, Trefoil, Shamrock
300 species are found in temperate and sub-tropical areas (not South East Asia or Australia).
Trifoliosis, otherwise known as bighead or geeldikkop, is a photosensitivity syndrome in animals that occurs when they ingest large amounts of, or are fed exclusively on, certain Trifolium species. The subject is reviewed by Kingsbury (1964), and by Watt & Breyer-Brandwijk (1962). Whether photosensitisation is primary or hepatogenous is not clear. The skin surfaces most likely to show the effects of photosensitivity are those which contact moisture when the animals are at pasture, namely the muzzle and the feet; for this reason, the disorder has been known as "dew poisoning". Stomatitis and ulceration of the tongue, i.e. sites not exposed to light, can also occur. In Australia the condition has been known as aphis disease but it is not due to ingestion of this insect but results from photosensitisation due to the ingestion of compounds present in Trifolium. Clover is also a common name for Melilotus.
- Trifolium arvense
- Rabbit-Foot Clover
Mechanical injury can occur from the hairy calyx on ingestion by animals forming, together with other objects, 'hair balls' (phytobezoars) (Muenscher 1951).
- Trifolium hybridum L.
- Alsike Clover, Bastard Clover, Swedish Clover
Ingestion of the plant may cause photodermatitis - a condition known as trifoliosis, bighead or geeldikkop - in animals (Mathews 1937, Watt & Breyer-Brandwijk 1962, Kingsbury 1964). According to Edwards (1941) and Muenscher (1951), contact with this plant can cause photodermatitis in man. Hardin and Arena (1974) state that contact with the leaves can cause dermatitis. Gardner & Bennetts (1956) include this species in a list of plants known or suspected of causing dermatitis. Rust fungi attacking the clover have been suspected of causing or contributing to the trifoliosis in animals (Steyn 1934) and could well be responsible for contact photodermatitis in man (see FUNGI - Pucciniaceae).
- Trifolium incarnatum
- Crimson Clover
The hairy inflorescences can form phytobezoars (Hurst 1942). Mechanical injury by hairy calyx can occur (Muenscher 1951).
- Trifolium pratense L.
- Red Clover, Purple Clover, Meadow Clover
Steyn (1934), Watt & Breyer-Brandwijk (1962), and Stuart (1979) note that ingestion of the plant by animals may cause photodermatitis - a condition known as trifoliosis, bighead, or geeldikkop. Gardner & Bennetts (1956) include this species in a list of plants known or suspected of causing urticaria or skin irritation. Rust fungi attacking the clover have been suspected of causing or contributing to the trifoliosis in animals (Steyn 1934) and could well be responsible for contact (photo)dermatitis in man (see FUNGI - Pucciniaceae). In a study of secondary photosensitisation in horses (Ames et al. 1994), it was noticed that a substantial proportion of the clover (red or white) in pastures where the horses had been grazing was infected with Cymadothea trifolii F.A. Wolf (fam. Mycosphaerellaceae), a mould that causes black blotch or sooty blotch disease in clover.
According to Stuart (1979), red clover flowers are applied in the treatment of burns, sores, and skin complaints, and are used internally to treat chronic skin conditions such as psoriasis and eczema.
- Trifolium repens L.
- White Clover
Hjorth (1968) recorded 0 positive patch test reactions from this plant.
The plant is thought to favour the formation of phytobezoars. Some strains of the plant contain a cyanogenetic glucoside which has goitrogenic effects for animals on ingestion; the presence of this compound and its relevant enzyme is genetically determined and a non-cyanogenetic strain has evolved (Watt & Breyer-Brandwijk 1962).
Ames et al. (1994) presented circumstantial evidence that white clover infected with black blotch disease was the cause of secondary photosensitisation in horses (see Trifolium pratense L. above).
- Trifolium subterraneum L.
- Subterranean Clover
Filmer (1929) described a painful dermatitis in cows that initially involved the outer surfaces and the ends of the teats then later the udder, perineum, vulva, lips, eyes, back and jugular furrow. He noted that the cows had been grazing a pasture dominated by subterranean clover, and that the disease bore similarities to trefoil dermatitis and clover sickness. Accordingly, a tentative diagnosis of photosensitisation by subterranean clover was made. However, other aspects did not wholly support this diagnosis, and in particular the observation that resolution took place whilst the cows were still being grazed on the clover.
135 species are found in the Mediterranean region, Europe, Asia, South Africa and Australia.
- Trigonella foenum-graecum L.
- Fenugreek, Sicklefruit
The plant is used as an ingredient in curry-powders and to perfume butter (Watt & Breyer-Brandwijk 1962). A principal constituent is anethole (Furia & Bellanca 1971). Anethole is the chief constituent of Oil of Anise (Pimpinella or Illicium) and Oil of Fennel (Foeniculum). A case of sensitivity (stomatitis) due to a denture cream containing Oil of Anise which was 90% anethole has been reported (Loveman 1938).
- Ulex L.
The is a genus of 10–20 species of spiny shrubs found in western Europe and northern Africa (Mabberley 2008). Some may be found in cultivation as ornamentals and as hedges (Hunt 1968/70). Their spines are capable of inflicting mechanical injury. The following species are most commonly encountered:
- Ulex europaeus L. — Gorse, Furze, Whin
- Ulex gallii Planchon — Dwarf Furze, Dwarf Gorse, Summer Gorse
- Ulex minor Roth — Small Furze, Dwarf Furze
- (syn. Ulex nanus T.F. Forster)
- Ulex parviflorus Pouret
Soldiers training on Woodbury Common near Exmouth, England have long been plagued by a mystery rash — the Woodbury rash. This is now believed to arise following inoculation under the skin of group A streptococci and/or other micro-organisms as a sequela to the mechanical injury inflicted by the spines of gorse. Fatal cases of streptococcal necrotising fasciitis (in a dog walker) and of staphylococcal Panton-Valentine leukocidin toxin-related illness (in a soldier) have been associated with scratches from gorse bushes sustained on Woodbury Common (Daily Mail Reporter 2006).
- Vachellia farnesiana Wight & Arn.
- (syns Acacia farnesiana Willd., Mimosa farnesiana L., Poponax farnesiana Raf., )
- Bunga Siam, Pokok Lasana
Cassie of perfumery is derived from this species.
- Vachellia seyal P.J.H. Hurter
- (syn. Acacia seyal Delile)
- Buffalo Thorn, Red Acacia, Shittim, Thirsty Thorn, White Whistling Thorn, White-galled Acacia, Mimosa Épineux
Two varieties are recognised, namely var seyal and var fistula Kyal. & Boatwr. (syn. Acacia fistula Schweinf.). These East African acacias bear thorns, some of which are considerably swollen, hollowed out, and pierced by an orifice. The wind playing on the empty swellings produces a whistling noise. These abnormally swollen thorns are believed to be insect galls, the orifice having been produced by the escaping causative insect. However, these hollow thorns may later become inhabited by ants, usually being arboreal ants of the genus Crematogaster Lund, fam. Formicidae (Bequaert 1922, Wheeler 1942). Thus, in addition to the potential of the thorns to inflict mechanical injury, handling these plants when growing in their natural habitat carries with it a risk of being bitten and/or stung by the ant inhabitants. Such plants may be described as super-nettles (Schmidt 1985).
This species is believed to be the shittah tree, the source of the shittim wood mentioned in the Book of Exodus (Chapters 25, 26, & 27), which was employed in making the Ark of the Covenant, tabernacle and altar, and for the coffins of pharoahs (Mabberley 2008).
- Vachellia sphaerocephala Seigler & Ebinger
- (syns Acacia dolichocephala Saff., Acacia sphaerocephala Cham. & Schltdl., Acacia veracruzensis Schenck)
This Central American species bears large thorns inside which ants make themselves at home (Menninger 1967).
- Vatairea guianensis Aubl.
- (syns Andira amazonum Mart. ex Benth., Ormosia pacimonensis Spruce ex Benth., Vatairea surinamensis Kleinhoonte)
- Quassia, Partridge Wood
The wood caused dermatitis and conjunctivitis when imported into Germany among some other South American timbers (Simatupang et al. 1967). The wood contains chrysophanic acid and physcion and their anthranols which are irritant (see Andira).
- Vatairea lundelli
Yields chrysophanic acid (Simatupang et al. 1967).
- Vicia faba
- Broad Bean
Favism is an acute disorder resulting either from the ingestion of the broad bean or the inhalation of its pollen, resulting in an acute haemolytic anaemia and acute hepatitis (Watt & Breyer-Brandwijk 1962). The disorder is genetically determined as a glucose-6-phosphate dehydrogenase deficiency (Kingsbury 1964). Symptoms may appear within minutes after inhalation of the pollen or after 5–24 hours after eating the bean.
- Vicia sativa
- Common Vetch, Tare
This species contains a photosensitising principle (North 1967).
- Vigna ungiculata
- (syn. Vigna sinensis)
- Horse Gram, Cherry Bean, Cow Pea, Garter Plant
This plant of tropical Asia forms pods which are eaten like French beans or used as horse- or cattle-fodder. Dermatitis reported from this plant is probably due to the batata louse (Trombiculum species) (Simons 1952).
- Vouacapoua americana Aublet
- (syn. Andira aubletii Benth.)
- Acapú, Bruinhart, Partridgewood, Tatbu, Wacapou
According to Freise (1932), the wood of acapú causes persistent itching papules. This species was later listed as an irritant wood causing dermatitis (Orsler 1973).
Nine species are found in Formosa, China and West Malaysia. (They are now regarded as belonging to the genus Callerya, which is closely related to Milletia).
Some have irritant properties possibly for the skin (Burkill 1935).
- Whitfordiodendron erianthum
The fruits are very acid (Burkill 1935).
- Wisteria sp.
McCord (1962) noted that an extract of this plant was available commercially for patch testing. Dermatitis from the plant has apparently not been reported.
- Xanthocercis zambesiaca Dumaz-le-Grand
- (syns Pseudo-Acacia zambesiaca, Pseudocadia zambesiaca Harms, Sophora zambesiaca Baker)
- Nyala Tree
The wood is a strong mucosal irritant. Wood-workers may develop severe irritation of the nose and throat (Codd 1951, Watt & Breyer-Brandwijk 1962).
- (syn. Esclerona)
15 species are native to tropical Africa, Madagascar and tropical Asia. Some yield good timber.
- Xylia xylocarpa Taub.
- (syn. Xylia dolabriformis Benth.)
The wood of Xylia dolabriformis, a Philippine species, is reported to be injurious (Heilig 1957). The sawdust of Xylia xylocarpa causes sneezing (Laslett 1894, Boulger 1908).
- Zapoteca formosa H. Hernández ssp formosa
- (syn. Calliandra gentryi Standley)
A herbarium note found by von Reis Altschul (1973) on a specimen of Calliandra gentryi collected in Mexico warned that the wood should not be used for fuel because the smoke will cause women to loose hair.
- Zollernia paraensis Huber
- (syn. Zollernia ulei Harms)
- Pao Santo
This Brazilian species is listed by Hanslian and Kadlec (1966b) as a wood that can produce dermatitis. Hausen (1970) cited Friese (1932) for a report of dermatitis from the wood.