Botanical name : Ricinus communis L.
Family : Euphorbiaceae
Origin : According to available literature, castor is indigenous to Eastern Africa and most probably originated in Ethiopia. It is also possible that castor is originated in the tropical belt of both India and Africa. In India, castor is known from very early days and is referred to in Sanskrit literature.

Castor plant belongs to Euphorbiaceae family. A large number of cultivars or types exist under Ricinus communis.Papova (1926) divided the species into 6 sub-species on ecogeographical grouping.

1) Ricinuc communis var. africanus
2) Ricinuc communis var.chinenesis
3) Ricinuc communis var.maxicanus
4) Ricinuc communis var.pericus
5) Ricinuc communis var.sanguineus
6) Ricinuc communis var.zanzibarinus

Castor belongs to the genus Ricinus, a member of the Euphorbiaceae, which contains a vast number of plants mostly native to the tropics. The genus Ricinus is considered to be monotypic and R. communis is the only species, which includes many polymorphic types. The cultivated types are dwarf annuals. Castor plants have well-developed root system with thick horizontal roots. Tap root looks like extension of the stem below the soil. The stem is erect, circular in section, partially hollow, glabrous, and smooth with good branching. Stem is either red or green or with shades of both. The stem is marked by well-defined nodes from each of which a leaf is arises. The lower internodes are shorter and their length increases with height. Leaves are alternate, large, and palmate with 5-11 lobes acuminate margins notched, serrate or indented. They are carried on long stout petioles. The inflorescence is borne terminally on the main and lateral branches. Flowers are large, in terminal sub panicled racemes, monoecious, apetalous, the upper portion of the raceme being occupied by the female flowers and the lower by male flowers The whole inflorescence may reach a length of 90 cm. The flowers are wind and insect pollinated and from 5 to 46 % natural pollination occurred. The fruit is round glaucous capsules with three projecting sides covered with tough spines or smooth, 3 loculed and three seeded. Seeds are albuminous, anatropous, broad, oval, compressed with a marked caruncle and longitudinal raphe. The testa is thin, brittle, varying in colour and mottling. Below the testa is a thin legmen, covering a whitish oily endosperm containing the embryo.