Prota 11(1): Medicinal plants/Plantes médicinales 1
Taxon 55(2): 413 (2006).
n = 17
Monadenium lugardiae N.E.Br. (1909).
Origin and geographic distribution
Euphorbia lugardiae occurs in Malawi, Zambia, Botswana, Zimbabwe, Mozambique and South Africa.
In Zimbabwe and South Africa a few drops of stem or root latex are mixed in porridge or milk and taken to treat ascites, stomach-ache, chest pain, headache, measles, pneumonia and asthma; the latex is also taken as an abortifacient. The latex is a violent purgative, and can cause vomiting and haemorrhagic gastroenteritis, cirrhosis of the liver and sometimes death. It is also used to expel worms in dogs. The latex taken together with plant sap of Portulaca quadrifida L. has been applied as a remedy for gonorrhoea. In South Africa plant ash is rubbed into scarifications to treat rheumatic pain. Consumption of the root can cause hallucinations and delirium, and a piece of the root is taken by diviners to see visions and to make prophecies. Eating the raw root produces a burning sensation in the mouth and gullet.
Euphorbia lugardiae is grown as an ornamental pot plant.
The latex from the aerial parts and a methanol extract from the stem had a dualistic effect on isolated guinea-pig ileum, as they had contractile activity at lower concentrations, but an inhibitory effect on the contractions at higher concentrations.
When 1 ml of pure or water-diluted latex from the aerial parts (at concentrations of 10% or 1%) was given orally to 3-month-old rats, all rats died within 20 minutes. Concentrations of 0.1% or 0.01% caused severe diarrhoea lasting 7 days and a 10–15% loss in weight. The latex is very acid, with a pH of as low as 2, and can cause dermatitis. The latex also showed significant insecticidal activity in vitro.
Monoecious, succulent shrub up to 60 cm tall, branching from the base, erect or slightly decumbent; roots thick and fleshy; stems cylindrical, up to 3 cm in diameter, with flattened tubercles c. 1.5 cm × 1 cm in a diamond-shaped pattern, with circular leaf scars c. 2 mm in diameter at apex. Leaves arranged spirally, crowded towards the stem apex, simple, almost sessile; stipules modified into a cluster of 3–5 soft spines up to 2 mm long, soon falling; blade obovate, up to 9 cm × 4 cm, base cuneate, apex rounded, margins wavy, fleshy, minutely short-hairy, pinnately veined. Inflorescence an axillary cyme, consisting of clusters of flowers, each cluster called a ‘cyathium’; peduncle 5–8 cm long and branches 2–4 mm long; bracts fused into a cup c. 7 mm × 7 mm, shortly notched between acute lobes, with prominent midveins, often tinged pinkish; cyathia c. 4 mm in diameter, with cup-shaped involucre, cream with yellow rim, 5-lobed with lobes c. 1 mm × 1.5 mm, toothed, with 1 horseshoe-shaped gland c. 2 mm long, each involucre containing 1 female flower surrounded by many male flowers. Flowers unisexual; male flowers sessile with bracteoles c. 2.5 mm long, fringed, perianth absent, stamen c. 4 mm long; female flowers with pedicel up to 8 mm in fruit, perianth 3-lobed, c. 2.5 mm in diameter, ovary superior, 3-celled, styles 3, c. 1.5 mm long, fused at base, deeply bifid at apex. Fruit a 3-lobed capsule c. 6 mm × 6 mm, with a pair of fleshy crested ridges along the ribs, 3-seeded. Seeds oblong, c. 3.5 mm × 1.5 mm, 4-angled, minutely rough, pale brownish grey, caruncle cap-shaped, c. 1 mm in diameter, on a short, thin stalk.
Euphorbia comprises about 2000 species and has a worldwide distribution. Monadenium (about 70 species in continental Africa) had always been kept separate from Euphorbia, but recent molecular analyses found Monadenium to be nested within Euphorbia, and it is therefore included within Euphorbia, as section Monadenium in subgenus Euphorbia.
Euphorbia lugardiae occurs on granite outcrops, in sandy soil among rocks in wooded grassland and open Brachystegia woodland, and also in shade on termite mounds, often in colonies, at 100–1100 m altitude.
As a pot plant Euphorbia lugardiae needs full sun to light shade, and a well-drained soil mix consisting of 2 parts sand to 1 part loam and 1 part peat moss. After watering the plants should be allowed to dry thoroughly before watering again. A single fertilizer application is recommended during the growing season. Too much water and fertilizer will cause root rot. During the cold season, only enough water should be given to keep the leaves from shrivelling and dropping off.
Euphorbia lugardiae is mainly propagated from stem cuttings; stem tips 10–15 cm long are used. After cutting, the stems are dipped in charcoal dust to seal the cut and then left to form callus for a week before inserting the cutting into the soil. Cuttings should root in 6–8 weeks.
Genetic resources and breeding
Euphorbia lugardiae is rather uncommon in its distribution area, but there are no signs that it is threatened by genetic erosion.
Euphorbia lugardiae has several medicinal uses, but chemical analyses and pharmacological evidence of its usefulness is lacking. Additional research is therefore warranted.
• Bruyns, P.V., Mapaya, R.J. & Hedderson, T., 2006. A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data. Taxon 55(2): 397–420.
• 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.
• Gundidza, M., 1993. Toxicity of Monadenium lugardiae to albino rats. Zimbabwe Science News 27(4–6): 47.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• van Wyk, B.E. & Gericke, N., 2000. People’s plants: a guide to useful plants of southern Africa. Briza Publications, Pretoria, South Africa. 351 pp.
• De Smet, P.A.G.M., 1996. Some ethnopharmacological notes on African hallucinogens. Journal of Ethnopharmacology 50: 141–146.
• Gelfand, M., Mavi, S., Drummond, R.B. & Ndemera, B., 1985. The traditional medical practitioner in Zimbabwe: his principles of practice and pharmacopoeia. Mambo Press, Gweru, Zimbabwe. 411 pp.
• Gundidza, M., 1986. Insecticidal activity of Monadenium lugardae latex. Planta Medica 52(6): 558.
• Gundidza, M., 1990. Action of Monadenium lugardiae latex on guinea-pig ileum. Fitoterapia 61: 442–444.
• Gundidza, M., 1991. Effect of methanol extract from Monadenium lugardiae on contractile activity of guinea-pig ileum. Central African Journal of Medicine 37(5): 141–144.
• Lemke, C., 2005. Monadenium lugardiae. [Internet] Cal’s Plant of the Week, University of Oklahoma, Department of Botany & Microbiology, United States. http://www.plantoftheweek.org/ week289.shtml. Accessed November 2007.
• Steenkamp, V., 2003. Traditional herbal remedies used by South African women for gynaecological complaints. Journal of Ethnopharmacology 86: 97–108.
• Steinmann, V.W. & Porter, J.M., 2002. Phylogenetic relationships in Euphorbieae (Euphorbiaceae) based on its and ndhF sequence data. Annals of the Missouri Botanical Garden 89(4): 453–490.
Correct citation of this article:
Schmelzer, G.H., 2008. Euphorbia lugardiae (N.E.Br.) Bruyns. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.