Mucuna gigantea (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Cereal / pulse
Medicinal

Mucuna gigantea (Willd.) DC.

Protologue: Prodr. 2: 405 (1825).

Family: Papilionaceae (Leguminosae - Papilionoideae, Fabaceae)

Synonyms

• Mucuna quadrialata Baker (1871),
• Mucuna longipedicellata Hauman (1955).

Vernacular names

• Sea bean, burny bean (En).
• Liane cadoque, liane caïman, mort aux rats (Fr).
• Mtera (Sw).

Origin and geographic distribution

Mucuna gigantea is distributed in tropical Asia, Japan, Australia, Pacific Islands and Africa. In tropical Africa it is found from DR Congo to Kenya, Tanzania and Mozambique, also in Madagascar and other Indian Ocean islands.

Uses

The seeds of Mucuna gigantea are considered edible in Kenya. In India boiled seeds are sometimes eaten as a pulse, e.g. in the Andaman Islands. Aboriginals in Australia used to heat the seeds on hot stones or sand, remove the peel, and grind them to flour, which was then mixed with water, wrapped in leaves and baked.

Root decoctions of Mucuna gigantea are taken to treat gonorrhoea and schistosomiasis. In India the bark is applied externally to treat rheumatic complaints. Powdered seed is used as a purgative in Hawaii. The irritant hairs on the outside of the pods are mentioned as being used in criminal poisoning in Malaysia. In Vietnam they are mixed with food to get rid of rats.

Properties

Mucuna gigantea seeds contain 1.7–2% L-dopa (levodopa; L-3, 4-dihydroxyphenylalanine), an amino acid which stimulates the formation of the neurotransmitter dopamine in the brain. Dopamine lessens tremor experienced in Parkinson’s disease. However, opinions differ on the side effects and efficacy in the long run of L-dopa. Because of the presence of toxic compounds in the plant, it seems advisable to eat the seed only after prolonged soaking and boiling.

Description

• Large liana up to 30(–80) m long; stems initially covered with orange-brown bristle hairs, glabrescent.
• Leaves alternate, 3-foliolate; stipules 3–5 mm × 1 mm, deciduous; petiole 4–15 cm long, rachis 1.5–3.5 cm long; stipels needle-shaped, 2–3 mm long, persistent; petiolules c. 5 mm long; leaflets ovate or elliptical, 4–15 cm × 2–9 cm, the lateral ones oblique, acuminate and markedly apiculate at apex, rounded at base, thinly appressed hairy when young, soon glabrescent.
• Inflorescence an axillary, pendulous false umbel 10–35 cm long, with flowers on short lateral branchlets 5–10 mm long; peduncle 4–22(–30) cm long.
• Flowers bisexual, papilionaceous; pedicel 1–2.5 cm long; calyx cup-shaped, 10–13 mm long, 2-lipped, covered with fine grey hairs and long deciduous orange-brown bristle hairs, tube 7–11 mm long, lobes 2–3 mm long, the upper lip somewhat emarginate; corolla pale creamy-green, white or pale lilac, standard (2–)2.5–3.5 cm × (1.5–)2–2.5 cm, round, with sparse orange-brown bristle hairs, wings and keel (3–)3.5–4.5 cm long; stamens 10, 9 united and 1 free; ovary superior, 1-celled, style long, filiform, stigma small and terminal.
• Fruit a stiped pod, oblong or oblong-elliptical, 7–15 cm × 3–5.5(–6.5) cm × 1–2 cm, each margin with 2 wings, densely covered with orange-brown bristle hairs at first, becoming glabrous at maturity, 1–4(–6)-seeded.
• Seeds 2.5–3 cm × 2–3 cm × 1–1.5 cm, discoid, dark brown or densely mottled with rust brown or black, smooth, hilum extending around the seed-margin for c. three-quarters of the circumference.
• Seedling with hypogeal germination; first leaves scale-like or simple.

Other botanical information

Mucuna belongs to the tribe Phaseoleae and comprises about 100 species distributed pantropically. In tropical Africa about 10 species are present. Several subspecies have been distinguished within Mucuna gigantea, with subsp. quadrialata (Baker) Verdc. in Africa. However, Mucuna gigantea is very variable throughout its range and it seems not possible to retain subsp. quadrialata.

Initial growth of Mucuna gigantea is rapid: seedlings may attain a height of more than 1 m in 3 weeks. In Madagascar it flowers during the dry season. The flowers are much visited by humming-birds. The seeds are dispersed by sea currents. All green plant parts, including the flowers, become black when bruised or dried.

Ecology

Mucuna gigantea is essentially a littoral species found around the Indian Ocean, but in tropical Africa it also occurs inland. It is found in coastal scrub, on riverbanks, and near water in woodland and forest edges, up to 1800 m altitude.

Management

Mucuna gigantea is collected from the wild. The presence of the intensely irritant bristle hairs makes handling difficult.

Genetic resources

One accession from Kenya is kept in the National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu. In view of its widespread distribution Mucuna gigantea is not threatened by genetic erosion.

Prospects

Because of the toxic compounds in the seed necessitating long cooking and the presence of irritant hairs on the pods it is unlikely that Mucuna gigantea will become a more important food crop.

Major references

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• Dahal, K.R. & van Valkenburg, J.L.C.H., 2003. Mucuna Adanson. In: Lemmens, R.H.M.J. & Bunyapraphatsara, N. (Editors). Plant Resources of South-East Asia No 12(3). Medicinal and poisonous plants 3. Backhuys Publishers, Leiden, Netherlands. pp. 305–308.

• Dick, H., 1994. Burny bean - Mucuna gigantea. Australian Plants 17(138): 254, 256.

• du Puy, D.J., Labat, J.N., Rabevohitra, R., Villiers, J.-F., Bosser, J. & Moat, J., 2002. The Leguminosae of Madagascar. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 750 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.

Other references

• Eilittä, M., Bressani, R., Carew, L.B., Carsky, R.J., Flores, M., Gilbert, R., Huyck, L., St-Laurent, L. & Szabo, N.J., 2002. Mucuna as a food and feed crop: an overview. In: Flores, M., Eilittä, M., Myhrman, R., Carew, L.B. & Carsky, R.J. (Editors). Food and feed from Mucuna: current uses and the way forward. Proceedings of an international workshop. CIDICCO (International Cover Crops Clearinghouse), Tegucigalpa, Honduras. pp. 18–46.

• Friedmann, F., 1994. Flore des Seychelles: Dicotylédones. Editions de l’ORSTOM, Paris, France. 663 pp.

• ILDIS, 2002. World database of Legumes, Version 6,05. International Legume Database & Information Service. [Internet] http://www.ildis.org/. September 2004.

• Mackinder, B., Pasquet, R., Polhill, R. & Verdcourt, B., 2001. Leguminosae (Papilionoideae: Phaseoleae). In: Pope, G.V. & Polhill, R.M. (Editors). Flora Zambesiaca. Volume 3, part 5. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 261 pp.

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

• Polhill, R.M., 1990. Légumineuses. In: Bosser, J., Cadet, T., Guého, J. & Marais, W. (Editors). Flore des Mascareignes. Famille 80. The Sugar Industry Research Institute, Mauritius, l’Office de la Recherche Scientifique Outre-Mer, Paris, France & Royal Botanic Gardens, Kew, Richmond, United Kingdom. 235 pp.

• Rajaram, N. & Janardhanan, K., 1991. The biochemical composition and nutritional potential of the tribal pulse, Mucuna gigantea (Willd) DC. Plant Foods for Human Nutrition 41(1): 45–51.

• Wilmot-Dear, C.M., 1984. A revision of Mucuna (Leguminosae - Phaseoleae) in China and Japan. Kew Bulletin 39(1): 23–65.

• Wilmot-Dear, C.M., 1991. A revision of Mucuna (Leguminosae - Phaseoleae) in the Philippines. Kew Bulletin 46(2): 213–251.

• Wilmot-Dear, C.M., 1992. A revision of Mucuna (Leguminosae: Phaseoleae) in Thailand, Indochina and the Malay Peninsula. Kew Bulletin 47(2): 203–245.

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. Mucuna gigantea (Willd.) DC. In: Brink, M. & Belay, G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 22 December 2024.

• See the Prota4U database.