- genus of much-branched treelike or shrubby cacti with pronounced ribs and rounded needlelike spines and nocturnal flowers usually white
- A cereus is a plant form of cactus from subfamilies Cactoideae. It is characteristic by very prolonged bodies. Its are columnar growth cacti and also some epiphytic cacti. The name Cereus is from the Greek and Latin signifying a torch.
- A genus of plants of the Cactus family. They are natives of America, from California to Chile