A mandrake is the root of a plant, historically derived either from plants of the genus Mandragora found in the Mediterranean region, or from other species, such as Bryonia alba or the American mandrake which have similar properties. The plants from which the root is obtained are also called "mandrakes". Mediterranean mandrakes are perennial herbaceous plants with ovate leaves arranged in a rosette, a thick upright root, often branched, and bell-shaped flowers followed by yellow or orange berries. They have been placed in different species by different authors. They are highly variable perennial herbaceous plants with long thick roots and almost no stem. The leaves are borne in a basal rosette, and are variable in size and shape, with a maximum length of 45 cm (18 in). They are usually either elliptical in shape or wider towards the end (obovate), with varying degrees of hairiness.