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== Notes ==
== Notes ==
* '''Polyphyly:''' Modern molecular studies (Machado et al. 2006, Nyffeler 2010) suggest that ''Cereus'' as
* Modern molecular studies (Machado et al. 2006, Nyffeler 2010) show that ''Cereus'' as currently defined is polyphyletic, meaning it will likely be split or reorganized in the future.
* Joël Lodé maintains ''Monvillea'' as a separate genus, refusing to include it as a subgenus (Ebneria) within ''Cereus''.
* ''Cereus mortensenii'' is a taxonomic outlier due to its pseudocephalium; Lodé suggests it may be a natural hybrid between ''Cereus'' and ''Melocactus''.
* The genus ''Piptanthocereus'' is no longer recognized and its species are moved here.

Revision as of 14:38, 29 March 2026

Cereus
File:Cereus hildmannianus.jpg
Kingdom Plantae
Family Cactaceae
Subfamily Cactoideae
Tribe Cereeae
SubTribe Cereinae
Genus Cereus
Species
Notes Taxonomy follows Joël Lodé (2015).

Etymology

The name stems from the Latin word cereus, meaning "wax candle," referring to the straight, cylindrical, candle-like growth habit of the stems.

Description

Cereus is a genus of shrubby or treelike cacti, often reaching massive proportions with well-defined trunks. The stems are angular and strongly ribbed, featuring large, woolly areoles that typically lack long hairs. A unique exception is Cereus mortensenii, which is the only species in the genus to produce a dense, woolly pseudocephalium. The spines are usually sturdy and needle-like (aciculate).

The flowers are nocturnal, large, and funnel-shaped. They are mostly white, but can be yellowish or tinted with purple. Pollination is a nocturnal affair: night-blooming species are visited by hawkmoths (Sphingidae) and bats (such as Glossophaga and Leptonycteris). Flowers remaining open in the morning also attract hummingbirds like Chlorostilbon aureiventris.

The fruits are globose to ovoid, fleshy, and exhibit lateral dehiscence (splitting on the side). They are highly variable in color—greenish, yellow, red, or bluish. They contain large, black, tuberculate seeds. In their natural habitat, animals like the tapir (Tapirus terrestris) are known to assist in seed dispersal.

Habitat

The genus is incredibly adaptable, growing from sea level up to 3200 m in altitude. They are found in diverse environments across South America, including thorny thickets, dry forests, and rocky volcanic slopes. They can thrive both in deep shade and in full equatorial sun.

Distribution

A wide-ranging genus across South America and the Caribbean:

  • Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru, Uruguay, Venezuela, Guyana, French Guyana, and the Caribbean Islands (Grenada, Trinidad & Tobago).

Species

According to the Joël Lodé index, the genus includes 26 recognized species and several subspecies:

Notes

  • Modern molecular studies (Machado et al. 2006, Nyffeler 2010) show that Cereus as currently defined is polyphyletic, meaning it will likely be split or reorganized in the future.
  • Joël Lodé maintains Monvillea as a separate genus, refusing to include it as a subgenus (Ebneria) within Cereus.
  • Cereus mortensenii is a taxonomic outlier due to its pseudocephalium; Lodé suggests it may be a natural hybrid between Cereus and Melocactus.
  • The genus Piptanthocereus is no longer recognized and its species are moved here.