Cereus (plant)

Cereus is a genus of cacti including around 33 species of large columnar cacti from South America. The name is derived from Greek and Latin words meaning "wax", "torch" or "candle". 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.

Description

Cereus are shrubby or treelike, often attaining great heights. Most stems are angled or distinctly ribbed, ribs long, usually well developed and have large areoles, usually bearing spines. Cephalium is not present; C. mortensenii develops pseudocephalium. The flowers are large, funnelform, long, usually white, sometimes pink, purple, rarely cream, yellow, greenish, and open at night. The fruits are globose to ovoid to oblong, long, fleshy, naked, usually red but sometimes yellow, pulp white, pink or red. The seeds are large, curved ovoid, glossy black.

Taxonomy

The name Cereus originates in a book by Tabernaemontanus published in 1625 and refers to the candle-like form of species C. hexagonus. It was described by Philip Miller in 1754, and included all known cacti with very elongated bodies.
Ludwig Pfeiffer in 1838 distinguished Cephalocereus ; the name is derived from the Greek κεφᾶλή thus headed cereus, referring to the hairy pseudocephalium. Charles Lemaire described Pilocereus in 1839, now renamed as Pilosocereus. The name Pilocereus is derived from the Greek πῖλος, felted, hairy, thus hairy cereus, similar to the Latin pilosus, from which the name Pilosocereus was derived. Echinocereus was described in 1848 by George Engelmann; the name is derived from the Greek ἐχῖνος.
Nathaniel Lord Britton and Joseph Nelson Rose as well as Alwin Berger continued to divide Cereus into many genera. The 33 or so species that remain in the Cereus group are largely plants that have not been moved out of the genus rather than plants that have been included because they fit the description of Cereus. This inclusion-by-lack-of-exclusion makes for a very messy and unsatisfactory grouping.
Some sources include the genus Mirabella ''Cereus as a subgenus, C. subg. Mirabella''.

Species

, Plants of the World Online accepted the following species:

Subgenus	Image	Scientific name	Distribution
Mirabella		Cereus albicaulis Luetzelb.	North-east Brazil
Mirabella		Cereus alex-bragae M.Köhler	Goiás,Brazil
Mirabella		Cereus mirabella N.P.Taylor	Brazil
Oblongicarpi		Cereus fricii Backeb.	Colombia, Venezuela
Oblongicarpi		Cereus horrispinus Backeb.	Colombia, Venezuela
Oblongicarpi		Cereus mortensenii D.R.Hunt & N.P.Taylor	Venezuela
Oblongicarpi		Cereus repandus Mill.	Aruba, Colombia, Venezuela, Venezuela
Oblongicarpi		Cereus serruliflorus Haw.	Haiti
Ebneria		Cereus aethiops Haw.	Argentina to Uruguay
Ebneria		Cereus phatnospermus K.Schum.	Argentina, Bolivia, Brazil, Paraguay
Ebneria		Cereus saddianus P.J.Braun	Mato Grosso, Brazil
Ebneria		Cereus spegazzinii F.A.C.Weber	Argentina, Bolivia, Brazil, Paraguay
Cereus		Cereus bicolor Rizzini & A.Mattos	Brazil
Cereus		Cereus fernambucensis Lem.	Brazil
Cereus		Cereus forbesii C.F.Först.	Argentina, Bolivia, Paraguay
Cereus		Cereus gerardi N.P.Taylor	Tocantins,brazil
Cereus		Cereus hexagonus Mill.	Brazil, French Guiana, Guyana, Suriname, Venezuela
Cereus		Cereus hildmannianus K.Schum.	Argentina, Bolivia, Brazil, Paraguay, Uruguay
Cereus		Cereus ingens N.P.Taylor & M.Machado	Bahia, Minas Gerais
Cereus		Cereus insularis Hemsl.	Brazil
Cereus		Cereus jamacaru DC.	Brazil
Cereus		Cereus lamprospermus K.Schum.	Bolivia, Paraguay
Cereus		Cereus lanosus P.J.Braun	Brazil, Paraguay
Cereus		Cereus lepidotus Salm-Dyck	Colombia, Trinidad-Tobago, Venezuela
Cereus		Cereus pachyrrhizus K.Schum.	Paraguay
Cereus		Cereus pierre-braunianus Esteves	Brazil
Cereus		Cereus stenogonus K.Schum.	Argentina, Bolivia, Brazil, Paraguay
Cereus		Cereus trigonodendron K.Schum. ex Vaupel	Bolivia, Brazil, Peru
Cereus		Cereus vargasianus Cárdenas	Peru
Cereus		Cereus yungasensis A.Fuentes & Quispe	Bolivia

Synonyms

Species that have formerly been accepted include:Cereus adelmarii, syn. of Cereus phatnospermusCereus argentinensis, syn. of Cereus stenogonusCereus braunii, syn. of Cereus trigonodendronCereus cochabambensis, syn. of Cereus forbesiiCereus comarapanus, syn. of Cereus forbesiiCereus hankeanus, syn. of Cereus forbesiiCereus huilunchu, syn. of Cereus forbesiiCereus kroenleinii, syn. of Cereus phatnospermusCereus roseiflorus, syn. of Cereus stenogonusCereus tacuaralensis, syn. of ''Cereus stenogonus''

Distribution

The range includes Brazil, northern Argentina, Paraguay, Uruguay, and Bolivia; more rarely it can be found in Peru, Colombia, Guyana, Suriname, and Venezuela.

Uses

The fruits and stems of C. repandus are edible, as is the fruit of many species in the genus; some perhaps have a laxative effect. The wood has been used in making furniture and for firewood, and sliced stems have been used as a soap substitute. The stems can be broken open for their pulp, a source of water. The plant is also cultivated as a living fence.