Common names: Castor oil plant (English); kasterolieboom (Afrikaans); Rizinus (German); Omukuenu (Herero); |khéerà.s (Khoekhoegowab); Olumono (Oshiwambo)

Origin: Tropical Africa

Description

Annual herb or much-branched, often lax, shrub or small tree up to 4 m high. Stem softly woody, smooth, grey-green, sometimes flushed reddish, carrying distinct scars where leaves have fallen off. Leaves large and quite wrinkly, up to 30 cm in diameter, deeply 5- to 9-lobed, shiny dark to bright green, sometimes flushed reddish; veins distinct; margins finely toothed. Flowers reddish or cream, carried near branch tips. Fruit spiky, green, brown or red, 3 chambered, with 1 seed in each chamber; spiky layer peels off when the fruit are ripe. Seeds shiny, bean-like; ± 10 x 5 mm, mottled brown and white.

Distribution/Discussion

Cultivated in gardens as an ornamental and as a crop plant to produce castor oil. Extremely invasive, often growing in dense stands in road verges, cultivated lands, river banks and disturbed areas. All parts of the plant, but especially the seed, are highly toxic to humans and animals, including domestic stock and horses. Just one or two of the seeds, which seem to be very attractive to small children, can cause human death.