Ricinus caruncle promotes the dispersal of the seed by ants (myrmecochory). The name "Ricinus" is a Latin word for tick; the seed is so named because it has markings and a bump at the end that resemble certain ticks. The genus "Ricinus" also exists in zoology, and designates insects (not ticks) which are parasites of birds; this is possible because the names of animals and plants are governed by different nomenclature codes. The common name "castor oil" probably comes from its use as a replacement for castoreum, a perfume base made from the dried perineal glands of the beaver ("castor" in
Castor (star) dwarf companions are difficult to determine, but are both thought to have less than half the mass of the Sun. Castor B is an Am star, with particularly strong spectral lines of certain metals. Castor C is a variable star, classified as a BY Dra type. BY Draconis variables are cool dwarf stars which vary as they rotate due to star spots or other variations in their photospheres. The two red dwarfs of Castor C are almost identical, with masses around and luminosities less than 10% of the Sun. All the red dwarfs in the Castor system have emissions lines