A plant, Ricinus communis, belonging to the spurge family (Euphorbiaceae). Castor varies greatly in height and in color of foliage, stems, and seeds and also in size and oil content of the seeds. The palmately lobed leaves are borne more or less alternately. The main stem is terminated by a raceme (primary). After appearance of the primary raceme, branches on the main stem are each in turn terminated by a raceme. Growth continues sequentially as long as the plant lives, with branches arising from recently terminated branches. Thus a plant can have racemes in all stages of development from mature to prebloom. Mature racemes mostly have 10 to 70 capsules, each capsule containing three seeds. In frost-free areas castor can attain heights of 9 to 11 m (30 to 36 ft). Castor seeds are poisonous and also contain allergens.