Ricinus communis L. Euphorbiaceae Castor oil plant. Palma Christi. Distribution: Mediterranean, E Africa, India. The seeds themselves are pretty, brown, bean-like usually with gold filigree markings on them, and the interior of the seed is the source of castor oil. The outer coat of the seed is the source of the poison ricin, famous (infamous) for the umbrella murder of Georgi Markov on Waterloo Bridge in 1978. The KGB are alleged to have killed Georgi Markov, a dissident Bulgarian journalist, with a pellet containing 0.28mgm of ricin fired into his leg using a specially adapted air gun in an umbrella. While his symptoms were those of ricin poisoning, no ricin was ever found in the pellet that was extracted from his leg. Two seeds, chewed and ingested are said to be fatal, but most people vomit and get rid of the toxin. Ducks are resistant to ricin, and need to ingest more than 80 to be fatal! In Peru the leaves are used as a tea for stomach ache, although they contain small amounts of ricin. It is called Palma Christi in early herbals because of the five pointed leaves, which schematically represent a hand. It is a monotypic genus in the spurge family. Photographed in the Medicinal Garden of the Royal College of Physicians, London.