Prota 11(1): Medicinal plants/Plantes m้dicinales 1
Journ. Bot. (Morot) 7: 300 (1893).
Kia ya mamba, mubongwena, mbuba, mtobwe (Sw).
Origin and geographic distribution
Strophanthus courmontii occurs in east and south-eastern Africa, from southern Kenya through Tanzania, Malawi and eastern Zambia to Zimbabwe and Mozambique.
In Tanzania a root decoction is drunk to treat rheumatism and also as an aphrodisiac. The seeds of Strophanthus courmontii are used to make ordeal poison and arrow poison. Such poisoned arrows are still used in north-eastern Tanzania to kill animals that are damaging crops. In Malawi, Zimbabwe and southern Mozambique Strophanthus courmontii is used for making arrow poison as are several other Strophanthus species. The wood is used for making walking sticks.
From unripe seeds various cardiac glycosides (cardenolides) have been isolated, i.e. panstroside and sarmentocymarin, based on the aglycone sarmentogenin, and sarveroside, based on the aglycone sarverogenin. From ripe seeds the glycosides intermedioside, panstroside, sarmentocymarin and sarveroside were isolated. These glycosides are all highly toxic.
Deciduous liana up to 22 m long or less often a shrub up to 4 m tall, with white latex; stem up to 10 cm in diameter, with corky ridges to 5 cm ื 2 cm; branches dark grey to reddish brown, with compressed corky triangles at the nodes, later growing into ridges. Leaves decussately opposite, simple and entire; stipules absent; petiole 311 mm long; blade elliptical to ovate or obovate, 214 cm ื 2.56.5 cm, base rounded to cuneate, apex acute to acuminate, thinly papery, glabrous. Inflorescence a terminal dichasial cyme, on long or short branches or in the forks, almost sessile, 13-flowered; bracts ovate or narrowly ovate, 1.54 mm long, sometimes deciduous. Flowers bisexual, regular, 5-merous, fragrant; pedicel 17.5 mm long; sepals free, almost equal, ovate, 310 mm long, acute or apiculate, often with pink margins; corolla tube 2243 mm long, widening at 1535% of its length into a cup-shaped upper part, at the mouth 1735 mm wide, hairy inside, white turning yellow near the base and red turning purple near the apex, inside yellow with purple streaks, corona lobes subulate with a wide base, 26 mm long, apex obtuse, fleshy, yellow turning purple via red, corolla lobes ovate, 2057 mm ื 1027 mm, gradually narrowing into the acute apex, white turning yellow, with a violet band on the right margin; stamens inserted at 612 mm from the base of the corolla tube, included, anthers acuminate; ovary half-inferior, 2-celled, style 8.516 mm long, ending in a ringlike pistil head surrounding the minute stigma. Fruit consisting of 2 ellipsoid follicles 1226 cm ื 34.5 cm, with obtuse apex, 2-valved, divergent at 160200ฐ, wall thick and hard, glabrous, grey- or purplish black, many-seeded. Seeds spindle-shaped, slightly flattened, 1015 mm long, densely hairy, at the apex with a long beak up to 8.5 cm long, glabrous in lower half, upper half with long hairs, up to 7 cm long.
Strophanthus comprises 38 species, of which 30 occur in continental Africa, 1 in Madagascar and 7 in Asia, from India to South-East Asia. Strophanthus courmontii flowers towards the end of the dry season while leafless, and to a lesser extent during the rainy season. Mature fruits are present towards the end of the rainy season.
Strophanthus courmontii occurs in gallery forest or riverine thickets, less often in forest away from rivers, from sea-level up to 1400 m altitude.
Genetic resources and breeding
Strophanthus courmontii is rather widespread in eastern and southern Africa and not in danger of genetic erosion.
Strophanthus courmontii has so far mainly been used for making arrow poison, a use which is declining rapidly. Although it contains glycosides, its medicinal use will be limited and restricted to its area of distribution unless further studies reveal new possibilities.
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Correct citation of this article:
de Ruijter, A., 2006. Strophanthus courmontii Sacleux ex Franch. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes m้dicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.