They are native to the Caribbean, western Mexico through Central America to northern South America, with some species along the Andes down to southern Peru, and a concentration of species in northeastern Brazil.

Acting on the principle of priority, in 1922 Nathaniel Britton and Joseph Rose resurrected Linnaeus' Cactus.

[2] The red, wool-coated cephalium, said to resemble the fez worn by Turkish men during the late Ottoman Empire, gives the plant one of its common names, Turk's cap cactus.

The fruits of this genus are edible, and in the wild they are frequently dispersed by lizards and birds.

[5] As of September 2023[update], Plants of the World Online accepted the following species:[1] As of September 2023[update], Plants of the World Online accepted the following natural hybrids:[1] This Cactaceae article is a stub.