Prota 11(1): Medicinal plants/Plantes médicinales 1
A.DC., Prodr. 15(2): 98 (1862).
Origin and geographic distribution
Euphorbia crotonoides occurs from Sudan and Ethiopia southwards throughout East Africa and southern Africa.
In Ethiopia a root decoction is taken to treat stomach problems and hookworm infection. In East Africa the root bark is chewed and the sap is swallowed as a purgative to treat obesity. The latex is applied to warts and skin diseases. An infusion of the aerial parts is mixed with other plants and taken to treat malaria.
Monoecious, much-branched, annual herb up to 50(–100) cm tall, with spreading white hairs and white latex; branches longitudinally ridged to winged. Leaves alternate, simple; stipules glandular, dark red; petiole up to 5 cm long, 2-winged; blade linear-lanceolate to ovate, 3–14 cm × 0.5–6 cm, base tapering into the petiole, apex acute, margins almost entire to toothed, teeth gland-tipped, red, midvein winged on lower surface. Inflorescence an axillary or terminal cyme consisting of clusters of flowers, each cluster called a ‘cyathium’, in 3-branched umbels; branches up to 12 cm long; bracts narrower than leaves, with petiole up to c. 5 mm long; cyathia almost sessile, c. 2.5 mm × 3.5 mm, with a cup-shaped involucre, lobes quadrangular, c. 2 mm long, margin hairy, glands 4, transversely elliptical, c. 1 mm × 1.5 mm, yellow, turning brown then red, each involucre containing 1 female flower surrounded by many male flowers. Flowers unisexual; male flowers sessile, bracteoles fringed, perianth absent, stamen c. 3 mm long; female flowers with pedicel c. 3 mm long in fruit, ovary superior, densely hairy, 3-celled, styles 3, 2–2.5 mm long, fused to halfway, apex thickened, spreading. Fruit an almost globose capsule 6.5–7 mm in diameter, base truncate, with shallow longitudinal grooves, long-hairy, 3-seeded. Seeds ovoid or conical, 4-angled, c. 4.5 mm × 2.5 mm, apex rounded or acute, obscurely or distinctly warty, brown to grey or reddish black; caruncle absent.
Euphorbia comprises about 2000 species and has a worldwide distribution, with at least 750 species occurring in continental Africa and about 150 species in Madagascar and the Indian Ocean islands. Euphorbia crotonoides belongs to subgenus Eremophyton, section Pseudacalypha, a group consisting of annual or short-lived perennial herbs or shrubs with glandular or filamentous stipules, leafy bracts, 4 involucral glands, almost globose capsules on a short pedicel and warty seeds without a caruncle. In southern Africa the growth of Euphorbia crotonoides is more lush and the leaves are more ovate. Throughout the species range the size of the glandular teeth on the leaf margins varies considerably, as does the density of the hairiness and the colour of the seeds.
Several other Euphorbia spp. of section Pseudacalypha are used for medicinal purposes in tropical Africa. Euphorbia acalyphoides Hochst. ex Boiss. occurs from Sudan east to Somalia and Kenya, in Angola, and also in Yemen and Saudi Arabia. In Somalia the crushed herb or the latex is applied to fungal skin diseases. Euphorbia hadramautica Bak. occurs in Ethiopia and Somalia and possibly in northern Kenya; it is also found in Yemen, including Socotra. In Somalia the latex is applied to foot rot and foot abscesses in sheep and goats, and skin parasites of camels. Euphorbia systyloides Pax occurs from Kenya and Uganda south to Zimbabwe and Mozambique. In southern Uganda a leaf decoction with salt is taken to treat tapeworm infections. The leaves are eaten by goats and camels. The following species belong to Euphorbia section Eremophyton, which differs mainly from section Pseudacalypha by oblong, well exserted capsules and seeds with a cap-like caruncle. Euphorbia agowensis Hochst. ex Boiss. occurs in Ethiopia, Somalia, Kenya and Angola, and also in Yemen and India. In Somalia the crushed herb or the latex is applied to fungal skin diseases. Euphorbia polyantha Pax occurs in Ethiopia, Somalia, Kenya and Tanzania. In Somalia the latex is taken in milk as a purgative to treat stomach problems. In Tanzania a stem bark decoction is taken to treat stomach troubles and oedema.
Euphorbia crotonoides occurs on sandy and stony soils in open grassy woodland or disturbed localities, at 350–1250 m altitude.
Genetic resources and breeding
Euphorbia crotonoides is widespread and common and not threatened by genetic erosion.
Euphorbia crotonoides will probably remain of local importance as a medicinal plant.
• Carter, S. & Leach, L.C., 2001. Euphorbiaceae, subfamily Euphorbioideae, tribe Euphorbieae. In: Pope, G.V. (Editor). Flora Zambesiaca. Volume 9, part 5. Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 339–465.
• Gemedo-Dalle, T., Maass, B.L. & Isselstein, J., 2005. Plant biodiversity and ethnobotany of Borana pastoralists in southern Oromia, Ethiopia. Economic Botany 59(1): 43–65.
• Giday, M., Asfaw, Z., Elmqvist, T. & Woldu, Z., 2003. An ethnobotanical study of medicinal plants used by the Zay people in Ethiopia. Journal of Ethnopharmacology 85: 43–52.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Catley, A. & Mohammed, A.A., 1996. Ethnoveterinary knowledge in Sanaag region, Somaliland (Part 11): notes on local methods of treating and preventing livestock disease. Nomadic Peoples 38: 1–12.
• Eggli, U. (Editor), 2002. Illustrated handbook of succulent plants: Dicotyledons. Springer, Berlin, Germany. 554 pp.
• Hamill, F.A., Apio, S., Mubiru, N.K., Bukenya-Ziraba, R., Mosango, M., Maganyi, O.W. & Soejarto, D.D., 2003. Traditional herbal drugs of southern Uganda, 2: literature analysis and antimicrobial assays. Journal of Ethnopharmacology 84: 57–78.
• Heine, B. & Heine, I., 1988. Plant concepts and plant use; an ethnobotanical survey of the semi-arid and arid lands of East Africa. Part 3. Rendille plants (Kenya). Cologne Development Studies 8. Breitenbach, Saarbrücken, Germany. 120 pp.
• Hurskainen, A., 1994. Plant taxonomy of the Parakuyo (Tanzania). Nordic Journal of African Studies 3(2): 117–158.
• Samuelsson, G., Farah, M.H., Claeson, P., Hagos, M., Thulin, M., Hedberg, O., Warfa, A.M., Hassan, A.O., Elmi, A.H., Abdurahman, A.D., Elmi, A.S., Abdi, Y.A. & Alin, M.H., 1992. Inventory of plants used in traditional medicine in Somalia. 2. Plants of the families Combretaceae to Labiatae. Journal of Ethnopharmacology 37: 47–70.
Correct citation of this article:
Schmelzer, G.H., 2008. Euphorbia crotonoides Boiss. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.