Cactoideae (Webb. 1828) The majority of cacti share only one easily recognizable common characteristic: the complete absence of leaves. Etymology: Plants similar to Cacteae.Place of Origin: The entire American continent. There are some isolated populations in Africa and the Indian Ocean of unknown origin.
Maihuenioideae (P.Fearn 1996) They exhibit a cespitose growth habit, with persistent, small, and succulent leaves, which is exceptional within the Cactaceae family, and solitary flowers that are generally diurnal and brightly colored. They inhabit rocky, well-drained, and exposed soils. They possess C3 metabolism. Etymology: Plants similar to Maihuenia.Place of Origin: Chile (Maule, Ñuble, Biobío, and La Araucanía regions) and Argentina, mainly in the provinces of Neuquén, Mendoza, Río Negro, and Chubut.
Opuntioideae (K.Schum. 1898) Highly variable plants in habit, from caespitose to tree-like. They usually have leaves, although these are often not persistent. Almost all species exhibit strong segmentation. They have glochids and spines, in many cases barbed backward. Diurnal flowers. Etymology: Plants similar to Opuntia.Place of Origin: Virtually the entire American continent.
Pereskioideae (K.Schum. 1898) They have a tree-like or shrub-like form, with fully developed leaves. They exhibit CAM metabolism in the stems and C3 metabolism in the leaves. They possess spines, which in some cases are very large. Etymology: Plants similar to Pereskia.Place of Origin: In various regions of Central and South America.