Peniocereus

Peniocereus is a genus of vining cacti, comprising about 18 species, found from the southwestern United States and Mexico. They have a large underground tuber, thin and inconspicuous stems.
Its name comes from the prefix "penio-" (from the Latin "penis", meaning ‘tail’) and "Cereus", the large genus from which it was split.
Known as the desert night-blooming cereus, it also shares its common names of “night-blooming cereus” and “queen of the night” with many other similar cacti.
Species.
Species include: