genus of about 75 low-growing, cormose species of plants of the iris family (Iridaceae), native to the Alps, southern Europe, and the Mediterranean area and widely grown for their cuplike blooms in early spring or fall. The spring-flowering sorts have a floral tube so long that the ovary is belowground, sheltered from climatic changes. The flowers close at night and in dull weather. saffron, used for dye, seasoning, and medicine, is the dried, feathery, orange tip of the pistils of the lilac or white, autumn-flowering C. sativus of western Asia. The alpine species, C. vernus, is the chief ancestor of the common garden crocus. Dutch yellow crocus (C. flavus), from stony slopes in southeastern Europe, is another popular spring species, as is C. biflorus, tinged purple and with yellow throat, sometimes striped, from the Mediterranean.