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| The genera of Cactaceae |
Including Akersia Buining, Bolivicereus Cárdenas, Borzicactella H.Johnson ex F. Ritter, Borzicactus Riccob, Borzicereus Fric & Kreuz. (orth. var.), Cleistocereus Fric & Kreuz. (orth. var.), Clistanthocereus Backeb., Demnosa Fric, Gymnanthocereus Backeb., Hildewintera F. Ritter, Loxanthocereus Backeb., Maritimocereus Akers, Pseudoechinocereus Buining (nom. inval.), Seticereus Backeb., Seticleistocactus Backeb., Winteria F. Ritter, Winterocereus Backeb.
The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric; neither cephaliate nor pseudocephaliate. The plants terrestrial and self supporting, or epiphytic, or scrambling, or lithophytic; not producing aerial roots; branched; prostrate, or erect, or pendent; neither shrubby nor tree-like, or shrubby (usually), or tree-like (rarely, more or less); solitary, or clustering; to (0.2–)0.5–5.25 m high. The stems columnar, or not columnar. The main stem more or less cylindrical. The branches slender, cylindrical; to 30 cm long. The stems segmented, or not segmented; not annually articulating; ribbed and grooved. The ribs 5–30; longitudinal; low. The grooves wide. The plants conspicuously tuberculate (rarely), or not conspicuously tuberculate. The tubercles often represeted by transverse furrows or notches. The tubercles connected by the ribs; borne in longitudinal series. The areoles associated with tubercles to not tubercle-associated; usually closely approximating; borne in longitudinal series; simple. The flowering areoles differing in form from the non-flowering ones to resembling the non-flowering ones (sometimes woollier in flowering parts). The areoles without glochids; with spines. The spines clustered; (3–)6–60; 0.2–7 cm long; with radials and centrals differentiated to showing little or no difference between radials and centrals. Central spines when identifiable, 1–10(–20). Radial spines 5–35. The spines straight, or curved. The mature stems leafless.
Flowering during the day. Pollination ornithophilous (pollinated by Hummingbirds). The flowers lateral; one per areole; narrowly, tubular (often flattened); sessile; small to large; 2.5–9 cm long; regular to somewhat irregular, or very irregular (e.g., in Borzicactus). The pericarpel with narrow overlapping scales subtending wool or hairs. The hypanthial tube sometimes curved, sometimes dorsally dilated, not S-shaped; not naked; with scales (covering it). The axils of the scales of the hypanthial tube not naked (hairy or woolly). The hypanthial tube spineless. The perianth yellow to orange, or red, or green. The perianth segments more or less erect (usually unexpanded, the imbricate segments not or only slightly spreading apically), or spreading (only in Borzicactus). The androecium including staminodes (Borzicactus), or without staminodes. Stamens adnate to the perianth (inserted in the throat and tube); and style exserted beyond the perianth; often in groups (in two series), or not grouped.
The mature fruit 0.9–6(–10) cm long; small, globose; green, or yellow, or red, or purple, or pink; naked, or not naked (sometimes with sparse hair tufts); without the persistent style characteristic of Cereus (q.v.); fleshy; without watery and translucent pulp; dehiscent (or bursting open), or indehiscent. The seeds small, black; pyriform (? - "obovate"); not encased in bony arils; without a mucilage sheath. The testa shiny. Cotyledons reduced or vestigial.
Natural Distribution. Peru, Bolivia, Argentina, Paraguay, Uraguay.
Classification. About 30 species. Subfamily Cactoideae. Tribe Trichocereeae.
Cf. Hunt, 1967.
Images. • Cleistocactus baumannii, as Cereus tweediei: Bot. Mag. 76 (1850). • Cleistocactus candelilla: © Zoya Akulova (2018). • Cleistocactus samaipatanus: © Zoya Akulova (2009). • Cleistocactus winteri (as Borzicactus aureispinus): © Zoya Akulova (2013). • Cleistocactus fieldianus (as Borzicactus): © Zoya Akulova (2010). • Cleistocactus tarijensis: © Zoya Akulova (2018). • Arrojadoa rhodantha, with Cleistocactus baumannii and Hylocereus stenopterus: Britton & Rose (1920).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2018 onwards. The genera of Cactaceae: descriptions, illustrations, identification, and information retrieval. Version: 14th November 2021. delta-intkey.com’.
