Castor Bean Seeds
he castor bean plant, Ricinus communis, is a "native of tropical Africa cultivated in several varieties for the oil found in its leaves and for its bold foliage."(Alber and Alber)
The "stalked leaves consist of usually eight radiating, pointed leaflets with slightly serrated edges and prominent central veins. Many varieties are green, but some are reddish brown."(Cooper and Johnson) The flowers are green and inconspicuous, but pink or red in the pigmented varieties. Many stamens are near the base and branching pistils are near the top of the Flower. The soft-spined fruits containing attractively mottled seeds are distinctive features of the plant.
It is grown as an ornamental in gardens, sometimes as a houseplant, and also grows as a weed.
It is an annual in the south and a perennial in the tropics, and it may reach "15 feet tall outdoors".
It is a woody herb belonging to the family of Euphorbiacea (Spurge).
The seeds from the castor bean plant, Ricinus communis, are poisonous to people, animals and insects. One of the main toxic proteins is "ricin", named by Stillmark in 1888 when he tested the beansí extract on red blood cells and saw them agglutinate. Now we know that the agglutination was due to another toxin that was also present, called RCA (Ricinus communis agglutinin). Ricin is a potent cytotoxin but a weak hemagglutinin, whereas RCA is a weak cytotoxin and a powerful hemagglutinin.
Poisoning by ingestion of the castor bean is due to ricin, not RCA, because RCA does not penetrate the intestinal wall, and does not affect red blood cells unless given intravenously. If RCA is injected into the blood, it will cause the red blood cells to agglutinate and burst by hemolysis.
Perhaps just one milligram of ricin can kill an adult.
The symptoms of human poisoning begin within a few hours of ingestion.
The symptoms are:
diarrhea, sometimes bloody.
Within several days there is:
a decrease in urine,
and a decrease in blood pressure.