Commonly found along roadsides and watercourses and disturbed soil. It is planted in gardens and cultivated for medicinal purposes. A declared invader plant that has to be eradicated. Originally from tropical Africa.
General: A much-branched woody bush or small tree that grows up to 4 m high.
Leaves: The large, shiny dark green or reddish leaves have serrated edges and look like a five- to nine-pointed star.
Flowers: The flowers are creamy coloured at the lower ends and reddish at the top. August to April.
Fruit: The spiky fruit can be green, brown or red, with one seed in each of its three compartments. The glossy seed is mottled in shades of brown and white.
• The toxic principle is ricin, a toxalbumin or plant lectin, Mm. 70 000 daltons, water soluble and poorly absorbed.
• Not totally denatured by proteolytic enzyme action.
• Enough absorbed from g.i.t. to be very toxic by oral route.
• Completely denatured by thorough heat treatment.
• Any ricin present in castor oil (a safe irritant purgative) is denatured by heating.
• Ricin: One of the most toxic substances known
• Castor oil seed: Horses most susceptible of farm animals, ruminants intermediate and poultry least
• Oil cake: Can be detoxified by heat, but should only be used as an organicfertilizer. In South Africa often not sufficiently detoxified
• Leaves: Eaten by stock without any effect.
• Latent period a few hours to days.
• High dose results in sudden collapse.
• Usually severe gastrointestinal irritation and its consequences:
- Severe purgation,
- watery to haemorrhagic diarrhoea,
- dehydration and
- weakness as a consequence.
• Anorexia, colic and tympany.
• Haemorrhagic, necrotic gastro-enteritis
• Lymph node necrosis
• Haemorrhages in g.i.t. and lymph nodes.
Karyorrhexis of lymphocytes in lymph nodes in addition to g.i.t. lesions.
• Symptomatic and supportive.
• Hyperimmune serum:
Very effective, but economically impractical and therefore not available.
(An aid to the diagnosis if available).
• Remember immunity to toxalbumins may develop.
• Castor oil cake should never be used as feed under any circumstances.
Colour photos. Final web-ready size: JPEG, 72 ppi. Photo 1: 21.3 kb; Photo 2: 18.3 kb; Photo 3: 81.8 kb; Photo 4: 9.7 kb. Original TIFF file housed at the Dept. of Paraclinical Sciences, Section Pharmacology and Toxicology, University of Pretoria.