(Greek, keros, wax; author, flower: the ancients believed that the bees visited the flowers for wax). Boraginaceae. About 6 species of annual or perennial herbs from Europe and Asia Minor, with alternate, glaucous leaves. and showy purple bracts. The best species is C. retorta, which has a unique appearance in the garden and is strongly recommended for more general cultivation. It is a hardy annual of easy culture.