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 sometimes used for a ceroid cactus, any cactus with a very elongated body, including columnar growth cacti and epiphytic cacti.
The specimen shown here is growing happily in the Melbourne Botanic Gardens and is the species C. uruguayanus.
This post is part of the Skywatch Friday meme,
and also part of the Floral Friday Fotos meme,
and also part of the Friday Greens meme.