PROTA homepage Prota 11(2): Medicinal plants/Plantes médicinales 2
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Riocreuxia polyantha Schltr.

Protologue
J. Bot. 33: 273 (1895).
Family
Asclepiadaceae (APG: Apocynaceae)
Chromosome number
2n = 22
Synonyms
Riocreuxia profusa N.E.Br.
Origin and geographic distribution
Riocreuxia polyantha occurs in Rwanda, Burundi, Tanzania, Malawi, Zambia, Angola, Zimbabwe and also in South Africa, Swaziland and Lesotho.
Uses
In Tanzania a root decoction is drunk to treat ascariasis. A root decoction, together with plant sap of Stephania abyssinica (Quart.-Dill. & A.Rich.) Walp. (Menispermaceae), is taken to treat pinworm.
Botany
A twining climber up to 3 m high; stems annual, 1.5–4(–7) mm in diameter, much branching, nodes with a ring of minute whitish hairs, internodes 4–27 cm long, short-hairy. Leaves opposite, simple and entire; petiole (1–)3–6(–9) cm long, short-hairy; blade ovate or elliptical-ovate, 3–9(–13.5) × 2–8(–18) cm, base deeply cordate, apex acuminate, short-hairy. Inflorescence an axillary, slender, paniculate cyme up to 17 cm long; bracts linear, c. 2 mm long, glabrous; peduncle branching at the node or at a distance into up to 4 branches, each branch branching once or twice to produce profusely flowering pseudo-umbels, each 10–30-flowered, many flowers opening simultaneously. Flowers bisexual, regular, 5-merous; stipules absent; pedicel (15–)20–35 mm long, glabrous; sepals linear or lanceolate, 2.5(–4) mm long, acute; corolla (13–)16(–28) mm long, straight, tube cylindrical, slightly inflated towards base, 10–14 mm × 3–4(–5) mm, both sides whitish-yellowish or pale green, glabrous, lobes linear-lanceolate, 4–8(–13) mm long, erect, long-acute, fused at apex to form an ellipsoid or almost globose cage-like structure 5(–8) mm in diameter, occasionally breaking free, sometimes orange-red to (pale) yellow, glabrous; corona almost globose, c. 1.5 × 1.5 mm, almost sessile, cream or yellowish, outer lobes forming 5 small pockets, shortly bifid, with c. 0.5 mm long horizontally orientated teeth, inner lobes linear, dorsiventrally compressed, 0.5–1.2 mm long, attached to the stamens. Fruit a pair of follicles, each follicle acutely divergent, cylindrical, apically tapering, (9–)15–17(–21) cm × 2–4 mm, many-seeded. Seed oblong-elliptical, dorsiventrally compressed, 8–10 mm × c. 2.5 mm, dark brown or blackish with a paler margin, coma c. 2 cm long.
Riocreuxia comprises 8 species, which all occur in Africa.
Ecology
Riocreuxia polyantha occurs in forest margins, montane and riverine forests, wooded savannas and thickets, from sea-level up to 1800 m altitude. Riocreuxia polyantha flowers in East and South East Africa from December–May with peaks from March to April, and in southern Africa from September–April with peaks from January to February.
Genetic resources and breeding
Riocreuxia polyantha is widespread and relatively common, and not in danger of genetic erosion.
Prospects
Riocreuxia polyantha will remain of local importance as a medicinal plant.
Major references
• Haerdi, F., 1964. Die Eingeborenen-Heilpflanzen des Ulanga-Distriktes Tanganjikas (Ostafrika). In: Haerdi, F., Kerharo, J. & Adam, J.G. (Editors). Afrikanische Heilpflanzen / Plantes médicinales africaines. Acta Tropica Supplementum 8: 1–278.
• Masinde, P.S., 2005. A revision of the African genus Riocreuxia Decne. (Apocynaceae: Asclepiadoideae-Ceropegieae). Kew Bulletin 60: 401–434.
Other references
• Dyer, R.A., 1980. Asclepiadaceae (Brachystelma, Ceropegia, Riocreuxia). In: Leistner, O. (Editor). Flora of southern Africa Vol. 27(4). Government Printer, Pretoria. pp. 1–91.
Author(s)
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
A. Gurib-Fakim
Faculty of Science, University of Mauritius, Réduit, Mauritius
Associate editors
R. Arroo
Leicester School of Pharmacy, Natural Products Research, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
Photo editor
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Schmelzer, G.H., 2010. Riocreuxia polyantha Schltr. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(2): Medicinal plants/Plantes médicinales 2. [CD-Rom]. PROTA, Wageningen, Netherlands.

obtained from Zimbabweflora




obtained from Zimbabweflora