Jacquemontia tamnifolia (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Vegetable
Medicinal
Ornamental
Forage / feed
Food security

Jacquemontia tamnifolia (L.) Griseb.

Protologue: Fl. Brit. W. I. 5: 474 (1862).

Family: Convolvulaceae

Chromosome number: 2n = 18

Synonyms

Ipomoea tamnifolia L. (1753), Jacquemontia capitata (Desr.) G.Don (1837).

Vernacular names

Hairy cluster-vine (En). Kikopwe (Sw).

Origin and geographic distribution

Jacquemontia tamnifolia occurs throughout Africa, including Madagascar and other Indian Ocean islands; it is also found in tropical America.

Uses

In Kenya and Tanzania the leaves of Jacquemontia tamnifolia are collected from the wild and eaten as a cooked vegetable; in Ghana they are added to soup. The plant is also a good fodder for all livestock. In Nigeria crushed leaves are applied against headache and in Senegal dried powdered leaves, mixed with leaves of Sarcocephalus latifolius (Sm.) E.A.Bruce, are taken as a snuff to treat neuralgia. In Tanzania leaf sap is applied against conjunctivitis and ash of the plant mixed with castor oil is rubbed into scarifications to treat leprosy. Juice of leaves and roots is taken as an antidote to treat bites of green mamba snakes and a leaf infusion is used to wash wounds. With its dense inflorescences of bright blue flowers Jacquemontia tamnifolia is a beautiful ornamental climber.

Properties

Traces of hallucinogenic indole alkaloids are present in the seed of Jacquemontia tamnifolia. Plant extracts are slightly insecticidal.

Botany

Annual herb with several stems from the base, usually climbing or trailing, occasionally erect, appressed silky hairy. Leaves alternate, simple; stipules absent; petiole up to 5 cm long, densely hairy; blade ovate to oblong or cordate, up to 9 cm × 6 cm, base truncate to cordate, apex acuminate, margin entire, ciliate. Inflorescence a dense, hairy, head-like cyme c. 2.5 cm in diameter, supported by leaf-like to linear bracts; peduncle up to 12 cm long, silky pilose. Flowers bisexual, regular, 5-merous; sepals ovate-lanceolate, c. 5 mm × 1 mm, densely reddish hairy; corolla funnel-shaped, c. 1 cm long, blue, obscurely lobed, glabrous but with 5 hairy bands; stamens inserted at base of corolla tube, included; ovary superior, glabrous, 2–3-celled, style filiform, c. 7 mm long, stigma 2-lobed. Fruit a globose capsule c. 3.5 mm in diameter, glabrous, pale yellow, dehiscing with 4 or 6 valves, 4–6-seeded. Seeds ovoid, c. 3 mm long, brown, scabrid.

Jacquemontia comprises about 120 species, most of them restricted to tropical America. It seems related to Convolvulus and Hewittia.

Ecology

Jacquemontia tamnifolia is found in relatively humid locations in woodland, edges of thickets and grassland, and as a weed on cultivated fields, from sea-level up to 1100 m altitude.

Genetic resources

Jacquemontia tamnifolia is widespread and not in danger of genetic erosion.

Prospects

Jacquemontia tamnifolia will remain a minor vegetable of local importance only. Its nutritional, medicinal and ornamental values deserve further investigation.

Major references

• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 960 pp.

• 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.

• Ruffo, C.K., Birnie, A. & Tengnäs, B., 2002. Edible wild plants of Tanzania. Technical Handbook No 27. Regional Land Management Unit/ SIDA, Nairobi, Kenya. 766 pp.

Other references

• 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.

• 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

Correct citation of this article

Jansen, P.C.M., 2004. Jacquemontia tamnifolia (L.) Griseb. [Internet] Record from PROTA4U. Grubben, G.J.H. & Denton, O.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. <http://www.prota4u.org/search.asp>.

Accessed 21 December 2024.

• See the Prota4U database.