Ricinus communis (Bekele-Tesemma, 2007)
| Ricinus communis (Bekele-Tesemma, 2007) |
Ricinus communis Euphorbiaceae Indigenous to Africa
Common names
- English: Castor-oil plant
- Agewgna: Chakmi
- Amargna: Gulo
- Guragigna: Kobo, Kuwobo
- Oromugna: Qobo, Obo
Ecology
A shrubby tree growing over a wide range of altitudes all over Africa, preferring humus‑rich and disturbed ground. In Ethiopia, it is found in Moist and Wet Kolla, Weyna Dega and Dega agroclimatic zones of almost all regions, 400–2,700 m.
Uses
Medicine (castor oil), oil (seeds).
Description
An evergreen shrub or tree to 5 m (many different varieties). Stems often red, hollow with age, well-marked leaf nodes and leaf scars.
- LEAVES: Large compound palmate leaves to 50 cm across with 5–11 lobes, the edge toothed, on a long hollow leaf stalk. Young leaves soft, shiny, dark redgreen above.
- FLOWERS: Crowded on upright spikes to 60 cm, male flowers with creamy‑yellow stamens at the base; female flowers with soft green spines and 3 bright red divided stigmas at the top.
- FRUIT: Round, green‑brown capsules, spiny, to 2.5 cm across, split to set free 3 seeds, grey‑purple‑brown, shiny and spotted with a small white structure (caruncle) at one end.
Propagation
Seedlings, direct sowing at site.
Seed
Collect mature fruits before they split open. Germination is good and fast, about 90 % after three weeks. About 1,300 seeds per kg.
- Treatment: Not necessary.
- Storage: Stores well for 2–3 years.
Management
A fast-growing but short-lived plant. Can be grown as a fallow plant and on cropland. Often found in homesteads.
Remarks
The plant is drought and termite resistant. The seed coat and leaves are poisonous to animals, including poultry. Even the oil residue can only be used as stock feed if specially treated. It can, however, be used as an organic manure. The seeds yield up to 50% oil. The oil has many industrial uses. For medicinal purposes, the oil extract must be heated to neutralize the strong poison, ricin. Even a few seeds can kill if they are chewed, so take care with children. The oil is best used as a body lotion but was commonly used as a purgative in the Western world until better products replaced it.
