Pilosocereus is a genus of cacti distributed throughout Mexico, the Caribbean, and Brazil. Containing many species, Pilosocereus includes both cacti that are quite commonly used in cultivation and some that are so rare as to be almost unknown outside botanical sources. The most common houseplant in the genus is P. pachycladus, which large nurseries produce in bulk and sell wholesale.This Brazilian species has a branched form and flowers at night, most easily identifiable by its lovely bright blue skin, which is complemented by its bright yellow spines. Pilosocereus cacti are mostly shrubby or tree-like, and several other species also have blue skin. Their flowers are shaped like tubes and often also blue, and they grow fleshy fruits. In cultivation, they are mostly grown in glasshouses because of their size and need for warmth in the winter. Their name derives from the Latin for “hairy cereus” because of their spiny aureoles, many of which have golden spines.