Cereus (genus)
 Cereus is a genus of cacti (family Cactaceae) including around 33 species of large columnar cacti from South America. The name is derived from Greek (κηρός) and Latin words meaning wax or torch. The genus Cereus was one of the first cactus genera to be described; the circumscription varies depending on the authority. The term cereus is also used to describe cacti in other genera with very elongated bodies including columnar growth cacti and epiphytic cacti.