The cactus family (Cactaceae) consists of about 131 genera and 1,866 species of flowering plants, almost all of which are found in the New World. Most cacti are adapted to arid environments, though a number of species are native to rainforests and other tropical or subtropical areas. Many have succulent photosynthetic stems and reduced leaves that are often modified as spines. The flowers are typically showy with numerous petals. The following is a list of some of the major genera and species in the family Cactaceae, arranged alphabetically by common name or genus.