Most—but not all—anole species have dewlaps, made of erectile cartilage (modified from the hyoid) and covered in skin, that extend from their throat areas. When not in use and closed it lies inconspicuously along the throat and chest. The size, shape, color and pattern of the dewlap vary extensively depending on species, and often it differs between the sexes, being smaller (in some absent) and/or less colorful in females. In a few species, including the Carolina, bark, Cochran's gianthead and slender anoles, it varies geographically in color depending on subspecies or morph. Very locally, distinct morphs of a single species that differ in dewlap colors (not just differences between sexes) may occur together. In addition to colors that are visible to humans, dewlaps can have ultraviolet reflectance, which is visible to anoles. The striped anole is the only species where it is asymmetrically colored, being brighter on one side than the other. In some species even juveniles have a dewlap. The West Cuban and Cuban stream anoles are the only where both sexes lack a dewlap, but it is reduced and diminutive in about a dozen other species.
