Crotalaria karagwensis (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Cereal / pulse

Crotalaria karagwensis Taub.

Protologue: Engl., Pflanzenw. Ost-Afrikas C: 204 (1895).

Family: Papilionaceae (Leguminosae - Papilionoideae, Fabaceae)

Synonyms

• Crotalaria lugardiorum Bullock (1932).

Origin and geographic distribution

Crotalaria karagwensis is distributed in Central and East Africa, from Cameroon to Ethiopia and southward to DR Congo and Tanzania.

Uses

The seeds of Crotalaria karagwensis are considered edible in Kenya.

Properties

Various toxic compounds (alkaloids and non-protein amino acids) are present in Crotalaria spp., but toxin levels in Crotalaria karagwensis are not known.

Description

• Erect, annual herb up to 1 m tall, often with spreading, weakly ascending branches from the base; stem appressed hairy.
• Leaves alternate, simple; stipules linear-subulate, up to 3.5 mm long; petiole 1–2 mm long; blade linear-lanceolate to elliptical, 1.5–11.5 cm × 2–12 mm, acute to rounded at apex, appressed hairy beneath.
• Inflorescence a terminal or axillary lax raceme 9–24 cm long, (6–)10–24-flowered.
• Flowers bisexual, papilionaceous; pedicel c. 5 mm long; calyx (4. 5–)6–8 mm long, upper lobes narrowly attenuate-triangular, longer than the tube; corolla yellow, standard elliptical, c. 9 mm × 7 mm, with reddish-purple veins, wings c. 7 mm × 2–3 mm, keel angular, 7–11 mm × 4 mm, with a long straight twisted beak; stamens 10, all joined; ovary superior, oblong, c. 3.5 mm long, 1-celled, style c. 7 mm long.
• Fruit an oblong, club-shaped pod, narrowed basally into a 2–3 mm long stipe, c. 2.5 cm × 3.5 cm × 0.5 cm, 15–34-seeded.
• Seeds obliquely heart-shaped, 1.5–4 mm in diameter, smooth.

Other botanical information

Crotalaria comprises about 600 species distributed throughout the tropics and subtropics, with about 500 species in tropical Africa. Crotalaria karagwensis belongs to section Crotalaria, subsection Longirostres. In this subsection levels of toxic compounds are in general relatively low, although most species contain the free amino acid γ-glutamyltyrosine.

Ecology

Crotalaria karagwensis occurs at 1100–2300 m altitude in grassland and woodland; it also persists on roadsides and in cultivated land.

Genetic resources

No germplasm collections of Crotalaria karagwensis are known to exist. In view of its wide distribution Crotalaria karagwensis is not threatened by genetic erosion.

Prospects

It is unclear to what extent Crotalaria karagwensis seeds are eaten in tropical Africa. More information is needed on the levels of toxic compounds in the seeds and appropriate processing methods to eliminate these compounds.

Major references

• Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.

• Gillett, J.B., Polhill, R.M., Verdcourt, B., Schubert, B.G., Milne-Redhead, E., & Brummitt, R.K., 1971. Leguminosae (Parts 3–4), subfamily Papilionoideae (1–2). In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 1108 pp.

• Pilbeam, D.J. & Bell, E.A., 1979. Free amino acids in Crotalaria seeds. Phytochemistry 18: 973–985.

• Polhill, R.M., 1982. Crotalaria in Africa and Madagascar. A.A. Balkema, Rotterdam, Netherlands. 389 pp.

• Thulin, M., 1989. Fabaceae (Leguminosae). In: Hedberg, I. & Edwards, S. (Editors). Flora of Ethiopia. Volume 3. Pittosporaceae to Araliaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 49–251.

Other references

• Hepper, F.N., 1958. Papilionaceae. In: Keay, R.W.J. (Editor). Flora of West Tropical Africa. Volume 1, part 2. 2nd Edition. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 505–587.

• ILDIS, 2005. World database of Legumes, Version 9,00. International Legume Database & Information Service. [Internet] http://www.ildis.org/. June 2005.

• Toussaint, L., Wilczek, R., Gillett, J.B. & Boutique, R., 1953. Papilionaceae (première partie). In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 4. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. 314 pp.

Author(s)

• M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Brink, M., 2006. Crotalaria karagwensis Taub. In: Brink, M. & Belay, G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 18 December 2024.

• See the Prota4U database.