Tulips (Tulipa) form a genus of spring-blooming perennial herbaceous bulbiferous geophytes (having bulbs as storage organs). The flowers are usually large, showy and brightly colored, generally red, pink, yellow, or white (usually in warm colors). They often have a different colored blotch at the base of the tepals (petals and sepals, collectively), internally. Because of a degree of variability within the populations, and a long history of cultivation, classification has been complex and controversial. The tulip is a member of the lily family, Liliaceae, along with 14 other genera, where it is most closely related to Amana, Erythronium and Gagea in the tribe Lilieae. There are about 75 species, and these are divided among four subgenera. The name "tulip" is thought to be derived from a Persian word for turban, which it may have been thought to resemble.