Castor bean (Ricinus communis
) is a perennial shrub, grown commonly for commercial purposes, for castor oil. It has thick, branched stems and triangular or elongated lobed leaves that are glossy with a prominent vein along the center. R. communis
produces clusters of cream or yellow flowers in the summer and large seed capsules that are green or red and covered with spines.
Lethal poisoning can occur in horses with ingestion of as little as 0.1 mg/kg of the toxins present in R. communis
seeds. The toxic chemicals found in R. communis
seeds include ricinine and ricin. Ricinine is a type of alkaloid which causes seizures. Ricin is a highly toxic type of toxalbumin that is responsible for inhibiting protein synthesis, in addition to DNA and RNA synthesis.
has been responsible for many poisoning incidents in horses, and in Europe, it is considered one of the most dangerous. This is partly due to the fact that horses tend to like the taste of R. communis
, as they find it palatable.