Prota 11(1): Medicinal plants/Plantes mιdicinales 1
Bull. Herb. Boiss. 6: 733 (1898).
Origin and geographic distribution
Croton menyharthii occurs from southern Ethiopia and Somalia south throughout East and southern Africa south to Natal (South Africa).
In Somalia a decoction of fresh or dried roots is taken to treat dysmenorrhoea. Fresh or dried crushed leaves in water are drunk to treat hepatitis and tapeworm. Crushed root bark in water is taken to treat intestinal obstruction. In East Africa a root decoction is taken to treat influenza and malaria. In Kenya the Pokomo people inhale the smoke of burnt leaves to ease pregnancy and menstruation pains.
A methanol extract of the leaves or twigs showed significant antiplasmodial activity in vitro, while a water extract was inactive.
Monoecious, much-branched shrub up to 5 m tall; young twigs densely covered with yellowish scales, older twigs pale greyish brown. Leaves alternate, simple and entire; stipules tiny, soon falling; petiole 25(9) mm long; blade elliptical-ovate to ovate-lanceolate, 2.57(11) cm Χ 13(4.5) cm, base rounded to shallowly cordate, with 2 minute basal glands, apex obtuse to notched, thinly stellate hairy and yellowish above, covered with shiny silvery to cream-coloured scales below. Inflorescence a slender terminal raceme up to 3(5) cm long at the end of side-shoots, covered with yellowish scales, mostly with male flowers in upper part and 14 female flowers at base. Flowers unisexual, 5-merous, regular, pale yellow-green; male flowers with pedicel 25 mm long, sepals ovate, c. 2 mm long, petals linear-oblong to linear-oblanceolate, c. 2 mm long, margin ciliate, stamens 1215, free; female flowers with pedicel 23 mm long, extending to 4 mm in fruit, calyx lobes ovate, c. 2 mm long, petals absent, ovary superior, rounded, densely scaly and stellate hairy, yellowish brown, brown or black, 3-celled, styles 34, deeply 2-fid, c. 2.5 mm long, spreading or incurved. Fruit a 3-lobed capsule 67 mm Χ 79 mm, covered with yellowish scales, black-spotted, 3-seeded. Seeds ellipsoid to ovoid, c. 6 mm Χ 4 mm, brown or greyish, shiny.
Croton comprises about 1200 species and occurs throughout the warmer regions of the world. It is best represented in the Americas; about 65 species occur in continental Africa and about 125 in Madagascar. Several other medicinally used species of Croton occur in East Africa. Croton polytrichus Pax is a lax shrub or small tree occurring from Sudan south to Zambia. In East Africa an extract of its roots is taken to treat headache and labour pain. Root powder, alone or mixed with that of Croton dichogamus Pax, is mixed with porridge or tea to treat impotence and colds. A root decoction is taken to treat irregular menstruation. Croton scheffleri Pax is a shrub or small tree occurring from Kenya to Zambia. In northern Kenya its roots are soaked in water and the water is taken to treat malaria and fever. Croton somalensis Pax occurs in Ethiopia, Somalia and northern Kenya. In Kenya the Maasai people drink a decoction of its roots to treat fever and malaria. The wood is used in house construction. Croton steenkampianus Gerstner (Tonga croton) occurs in Tanzania, southern Mozambique and South Africa. The Zulu people inhale the vapour of a decoction of its fresh leaves to treat general body pain. Extracts have shown antimalarial activity. Croton talaeporos Radcl.-Sm. occurs in southern Somalia and Kenya. In southern Kenya a root infusion is taken as a remedy for colds and stomach complaints.
Croton menyharthii occurs in deciduous bushland, dune bushland and thickets, from sea-level up to 1300 m altitude.
Genetic resources and breeding
There are no signs that Croton menyharthii is threatened by genetic erosion.
Croton menyharthii has several local medicinal uses, e.g. against menstrual pain, malaria and tapeworm, but nothing is known about the compounds that might be responsible for these actions. The leaves and twigs show significant antiplasmodial activity. More research is warranted to evaluate the potential of the species.
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Correct citation of this article:
Schmelzer, G.H., 2007. Croton menyharthii Pax. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes mιdicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.