Melianthus species

Abstract

DISTRIBUTION: • M. comosus has a wide distribution, mainly in the dry interior of South Africa, while • M. major occurs only in the Western Cape. • The genus Melianthus is restricted to southern Africa.

BOTANICAL DESCRIPTION: Melianthus comosus. General: A sturdy, woody multi-branched shrub, up to 3 m high. All parts produce a strong, unpleasant smell when touched or bruised. Leaves: Grouped towards the ends of the branches. Greyish-green, pinnately compound with + 5 pairs of toothed leaflets. Leaf stalks and midribs are winged. When touched, the leaves give off a distinctive odour. Flowers: Small green flowers with bright red petals, in clusters below the leaves. Fruit: A four-winged capsule. Each capsule contains a glossy round seed.

Melianthus major General: A large sturdy, woody multi-branched shrub. All parts produce a strong, unpleasant smell when touched or bruised. Leaves: Large grey-green leaves, pinnately compound with + 5 pairs of toothed leaflets. Leaf stalks and midribs are winged. When touched, the leaves give off a distinctive odour. Flowers: Large clusters of dark purplish-red nectar-rich flowers at the ends of the branches.

TOXIC PRINCIPLE: Six main toxic principles have been extracted: hellibrigenin 3-acetate and 5 new bufadienolides.

SYSTEMS AFFECTED: Cardiovascular system.

CLINICAL SIGNS: The plants seldom cause poisoning, although some mortalities have been reported in equines and ruminants when grazing is scarce. See also: Syndrome of Cardiac Glycoside Intoxication – “Tulp poisoning”.