African poison ivy
Sprig in the Pretoria N.B.G., and a close-up view of the compound leaf
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Anacardiaceae
Subfamily: Anacardioideae
Genus: Smodingium
E.Mey. ex Sond. in Harv. & Sonder
Species:
S. argutum
Binomial name
Smodingium argutum
  species range[1]

Smodingium argutum, the African poison ivy or pain bush,[2] is a southern African shrub or medium-sized tree in the Anacardiaceae, which has properties comparable to the American poison ivy,[3] as its sap contains heptadecyl catechols that are toxic to the skin.[1]

An immuno-chemical reaction is suspected as in other toxic anacardiaceous species.[3] It is monotypic in the genus Smodingium,[3] and was discovered in Pondoland by J. F. Drège during an 1832 expedition with the zoologist Andrew Smith.[3]

Description

It resembles Rhus species in habit and foliage. It is very variable in size, sometimes a woody shrub barely 1–2 feet high, or otherwise a tree of up to 6m. During summer it produces small, creamy green flowers arranged in large sprays.[1] The Greek generic name, meaning "durated mark",[3] alludes to its hard, flattened seeds, which are fitted with papery wings.[1] The margins of the alternately arranged, trifoliolate leaves are toothed, as suggested by its specific name, argutum, which means "sharp".[3] The foliage assumes attractive autumn colours. When damaged the twigs exude a creamy, poisonous sap, which turns black when the catechols contained in it polymerize to a melanin.[3]

Range

It occurs along the Mpumalanga escarpment, the uplands of Eswatini, the KwaZulu-Natal midlands, Pondoland and Transkei, southern Lesotho and the southern Free State.[1]

References

  1. ^ a b c d e "Smodingium argutum". Slide Collection (Paraclinical Sciences - Pharmacology & Toxicology). University of Pretoria.
  2. ^ Melissa Petruzzelloa. "7 Dangerous Plants You Should Never Touch". ENCYCLOPÆDIA BRITANNICA.
  3. ^ a b c d e f g Findlay, G.H. (31 August 1963). "Dermatitis of 'Poison Ivy' type from an indigenous South African plant - Smodingium argutum". S.A. Tydskrif vir Geneeskunde: 883–888.
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