03/09/2026
The castor oil plant (Ricinus communis) is a fast-growing shrub in the spurge family, native to East Africa but now grown worldwide in tropical and subtropical regions.
Key features:
Large, palmate (star-shaped) leaves, often reddish-purple in some varieties
Spiny seed capsules containing mottled, bean-like seeds
Can grow as a small tree (up to 12m) in tropical climates, or as an annual in cooler areas.
Uses:
- Seeds are pressed for castor oil — used in lubricants, soaps, paints, cosmetics, and industrial chemicals.
- Traditional medicinal use as a laxative.
- Biodiesel production in some regions.
Important caution:
The seeds contain ricin, a highly toxic compound — raw seeds are poisonous if chewed or swallowed. The oil itself is safe once properly processed, since the heat treatment destroys the ricin.
Growing conditions:
Thrives in well-drained soil, full sun, moderate rainfall. Drought-tolerant once established. Common in parts of Zimbabwe as a hardy hedge or boundary plant, and sometimes considered semi-wild/invasive since it self-seeds readily.