Ricinus communis L.
| Etymology | Genus | Named as the seeds resemble a Mediterranean sheep tick of the same name |
|---|---|---|
| Species | Growing in groups (communes) | |
| Family | Euphorbiaceae | |
| Synonyms | - | |
| Common Names | Castor Oil Plant, Castorbean | |
| Status | Exotic: Naturalised | |
| Form | Shrub | |
| Native Distribution | Eritrea, Ethiopia, Somalia | |
Diagnostics:
Growing in sunny scrublands, it has a form like the Manihot species, but can be differentiated from the lobed leaves having serrated margins. It is also not as common. The stem and branches are also distinctly segmented. The flowers lack petals, and only have green stamens and red stigmas extending out.
Interesting Facts:
The Castor Oil Plant is cultivated for its oil in the seeds at least 6,000 years ago by the Egyptians for lighting their lamps (University of Oxford, n.d.). It is still cultivated for the same oil today for lubrication and as a moisturer.
Despite its benefits the seeds contain the highly potent toxin called ricin. It is a ribosome-inactivating protein, which binds to cells and halts protein synthesis, causing cell death (Worbs et al., 2011). However, the process of extracting oil from the seeds denatures the toxic protein.
At a scrubland in Punggol End (2010).
Flowers, with pink-red stigmas sticking out.
Fruits.
References
Worbs, S., Köhler, K., Pauly, D., Avondet, M.-A., Schaer, M., Dorner, M. B., & Dorner, B. G. (2011). Ricinus communis intoxications in human and veterinary medicine—A summary of real cases. Toxins, 3(10), 1332–1372.
University of Oxford. (n.d.). Ricinus communis L. (Euphorbiaceae) – Castor oil plant. Plants 400. https://herbaria.plants.ox.ac.uk/. Accessed on 25-Oct-2025.
Author: Siyang
Posted: 2025-10-25