Prota 2: Vegetables/Légumes
2n = 16
Origin and geographic distribution
Pedalium murex is widespread in West, East and southern tropical Africa, Madagascar, and tropical Asia (from India and Sri Lanka to Indonesia).
In tropical Africa and India the leaves of Pedalium murex are collected from the wild and eaten boiled as a vegetable. In Tanzania the water in which the leaves have been boiled or a decoction of the root is drunk to treat venereal diseases. The viscid mucilage produced by the plant is used as a demulcent, diuretic and tonic, to treat gonorrhoea and dysuria, and to dissolve urethral stones. In India the plant is taken as an emmenagogue and ecbolic and the root is considered antibilious. The hard and prickly fruits are sold as medicine on Indian markets.
There is no information on the chemical composition of Pedalium murex leaves. Alkaloids, a greenish fatty oil, a little resin, phenolic acids, vanillin and flavones have been isolated from the fruits. The leaves and roots have been used in a clinical test with patients suffering from gonorrhoea; it was found to have no effect. Possibly because of its foetid smell, Pedalium murex is not grazed by livestock in Somalia.
Erect or ascending annual herb up to 75 cm tall, slightly succulent, with much -branching stem. Leaves opposite or alternate, simple; stipules absent; petiole up to 3.5 cm long; blade oblong-elliptical to obovate, up to 5 cm × 3.5 cm, base acute, apex rounded or truncate, margin irregularly toothed or lobed but sometimes entire, glabrous above, scaly-glandular below. Flowers solitary in leaf axils, bisexual, almost regular, 5-merous; pedicel slender, short, at base bearing nectarial glands; calyx deeply divided into lanceolate segments c. 2 mm long, persistent in fruit; corolla narrowly funnel-shaped, yellow, with tube up to 2.5 cm long and spreading, almost equal lobes c. 5 mm long, glabrescent or with a few hairs in the throat; stamens 4, included in corolla tube, filaments glandular hairy at base; ovary superior, 2-celled, style slender, stigma 2-lobed. Fruit an indehiscent capsule 1–2 cm × 0.5–1 cm, hard, pyramidal, 4 -angled, with a spreading spine c. 3 mm long at the base of each of the 4 angles, abruptly contracted below the spines, rounded to acute at apex, rugose or tuberculate, few-seeded. Seeds narrowly cylindrical, c. 6 mm × 1.5 mm, 3-angled towards the apex, black.
Pedalium comprises only a single species. Plants of Pedalium murex with prostrate stems can cover an area up to 1 m in diameter. The flowers open in the morning and close early to late in the afternoon. Plants can be found flowering throughout the year.
Pedalium murex is often found at the edge of beaches or in open grassland not too far from the seashore, up to 500 m altitude. It is a saline soil indicator, and occurs on sandy and limestone soils.
Genetic resources and breeding
Pedalium murex is widespread and not in danger of genetic erosion.
Pedalium murex will remain a minor leaf vegetable of only local importance. Its nutritional and medicinal properties need further research.
• Bhakuni, R.S., Shukla, Y.N. & Thakur, R.S., 1992. Flavonoids and other constituents from Pedalium murex. Phytochemistry 31(8): 2917–2918.
• Burkill, H.M., 1997. The useful plants of West Tropical Africa. 2nd Edition. Volume 4, Families M–R. Royal Botanic Gardens, Kew, United Kingdom. 969 pp.
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• Theobald, W.L. & Grupe, D.A., 1981. Pedaliaceae. In: Dassanayake, M.D. & Fosberg, F.R. (Editors). A revised handbook to the flora of Ceylon. Volume 3. Amerind Publishing Company, New Delhi, India. pp. 321–327.
• Watt, J.M. & Breyer-Brandwijk, M.G., 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd Edition. E. and S. Livingstone, London, United Kingdom. 1457 pp.
Correct citation of this article:
Jansen, P.C.M., 2004. Pedalium murex L. In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/Légumes. [CD-Rom]. PROTA, Wageningen, Netherlands.