cereus

Any of various large cacti (genus Cereus and related genera) of the western U.S. and tropical New World, including the saguaro and the organ-pipe cactus (Lemairocereus thurberi, also L. marginatus or C. thurberi). The genus Selenicereus (night-blooming cereus, or moon cactus), containing about 20 species, is known for its large, usually fragrant, night-blooming white flowers, among the largest in the cactus family. The queen-of-the–night (S. grandiflorus), the best-known night-blooming cereus, is often grown indoors.

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