Opuntioideae is a subfamily of the cactus family, Cactaceae. It contains 15 genera divided into five tribes. The subfamily encompasses roughly 220–250 species, and is geographically distributed throughout the New World from Canada, to Argentina. Members of this subfamily have diverse habits, including small geophytes, hemispherical cushions, shrubs, trees, and columnar cacti consisting of indeterminate branches or determinate terete or spherical segments.