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Ipomoea obscura (L.) Ker Gawl.

Protologue
Bot. Reg. 3: t. 239 (1817).
Family
Convolvulaceae
Chromosome number
2n = 30
Synonyms
Ipomoea fragilis Choisy (1845), Ipomoea acanthocarpa (Choisy) Asch. & Schweinf. (1867), Ipomoea inconspicua Bak. (1894).
Vernacular names
Obscure morning glory (En).
Origin and geographic distribution
Ipomoea obscura is widespread in tropical Africa, including Madagascar, the Mascarene Islands and the Seychelles, in South Africa, tropical Asia, northern Australia and Fiji.
Uses
The leaves of Ipomoea obscura are collected from the wild and eaten as a cooked vegetable in Kenya and added to soup in Nigeria. The plant is also used as fodder for all livestock. In DR Congo leaf sap is used to treat fits of insanity and in eastern Africa a root decoction is drunk against dysentery. In Indonesia a paste of the leaves, mixed with Argyreia mollis (Burm.f.) Choisy leaves and alcohol, is applied to open sores and pustules. Dried and powdered leaves are used to treat aphthae. Ipomoea obscura has also ornamental value as a climber with attractive flowers.
Properties
The leaves of Ipomoea obscura are mucilaginous and have a pleasant smell.
Botany
Annual or perennial herb with slender, twining or prostrate stem up to 3 m long, glabrous or patently hairy. Leaves alternate, simple; stipules absent; petiole up to 11 cm long; blade usually ovate, sometimes linear-oblong, 2–10 cm × 2–9 cm, base cordate, apex acuminate, margin entire or slightly undulate, pubescent or glabrescent. Inflorescence an axillary 1–few -flowered cyme; peduncle 1–14 cm long, slender; bracts minute. Flowers bisexual, regular, 5 -merous; pedicel 1–2 cm long, reflexed in fruit; sepals ovate to lanceolate, 4–8 mm long, often accrescent and reflexed in fruit; corolla funnel-shaped, 2–2.5 cm long, yellow, orange, cream or white with 5 darker bands, often centre dark purple; stamens inserted near base of corolla tube, included; ovary superior, glabrous, 2-celled, style c. 8 mm long, stigma 2-lobed. Fruit a globose to broadly ovoid capsule, 7–10 mm long, apiculate, opening with 4 valves, up to 4-seeded. Seeds ovoid, c. 4 mm long, black, pubescent.
Ipomoea comprises about 500 species and mainly occurs in the tropics. Ipomoea obscura is rather variable and several varieties have been distinguished. However, the occurrence of many intermediates makes these subdivisions questionable and without much practical use.
Ecology
Ipomoea obscura occurs in grassland, thickets, hedges, open forest, waste ground, roadsides and as a weed in cultivated fields, occasionally along sandy beaches, from sea -level up to 1800 m altitude.
Genetic resources and breeding
Ipomoea obscura is widespread and not in danger of genetic erosion.
Prospects
Ipomoea obscura will remain a minor vegetable, of local importance only. Its nutritional, medicinal and ornamental values deserve more research.
Major references
• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, United Kingdom. 960 pp.
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, United Kingdom. 686 pp.
• Dibiyantoro, A.L.H. & Schmelzer, G.H., 2001. Ipomoea L. In: van Valkenburg, J.L.C.H. & Bunyapraphatsara, N. (Editors). Plant Resources of South-East Asia No 12(2): Medicinal and poisonous plants 2. Backhuys Publishers, Leiden, Netherlands. pp. 312–320.
• Gonçalves, M.L., 1987. Convolvulaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 8, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 9–129.
Other references
• Deroin, T., 2001. Convolvulaceae. Flore de Madagascar et des Comores, familles 133 bis et 171. Muséum National d’Histoire Naturelle, Paris, France. pp. 11–287.
• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
• Verdcourt, B., 1963. Convolvulaceae. In: Hubbard, C.E. & Milne-Redhead, E. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 161 pp.
Author(s)
P.C.M. Jansen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
G.J.H. Grubben
Prins Hendriklaan 24, 1401 AT Bussum, Netherlands
O.A. Denton
National Horticultural Research Institute, P.M.B. 5432, Idi-Ishin, Ibadan, Nigeria
Associate Editors
C.-M. Messiaen
Bat. B 3, Résidence La Guirlande, 75, rue de Fontcarrade, 34070 Montpellier, France
R.R. Schippers
De Boeier 7, 3742 GD Baarn, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Jansen, P.C.M., 2004. Ipomoea obscura (L.) Ker Gawl. In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/Légumes. [CD-Rom]. PROTA, Wageningen, Netherlands.