Gesneriaceae is a family of flowering plants consisting of about 152 genera and ca. 3,540 species in the Old World and New World tropics and subtropics, with a very small number extending to temperate areas. Many species have colorful and showy flowers and are cultivated as ornamental plants. The genus Rehmannia has sometimes been included in Gesneriaceae but is now referred to the family Orobanchaceae. The family name is based on the genus Gesneria, which honors Swiss humanist Conrad Gessner.