| | The genera of Cactaceae |
~ Cleistocactus Lem.
The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric; 3–5 cm in diameter; cephaliate. The plants terrestrial and self supporting, or epiphytic, or scrambling, or lithophytic; basally branched; erect, or prostrate (sometimes bending over); shrubby; to 5 m high. The main stem more or less cylindrical. The branches slender, cylindrical. The stems not segmented; ribbed and grooved. The ribs 11–14; longitudinal; to 5 mm high. The grooves wide. The plants conspicuously tuberculate to not conspicuously tuberculate. The tubercles represented by V-shaped transverse furrows. The tubercles connected by the ribs; borne in longitudinal series. The areoles associated with tubercles to not tubercle-associated; fairly closely approximating; borne in longitudinal series; simple. The flowering areoles differing in form from the non-flowering ones (being woollier in the cephalia). The areoles without glochids; with spines. The spines clustered; 16–24; 0.4–3 cm long; with radials and centrals differentiated (0.7–3 cm long, the radials shorter). Central spines 4–7 ("about 6"). Radial spines 12–18 ("about 15"). The spines straight. The mature stems leafless.
Flowering during the day. Pollination ornithophilous (pollinated by Hummingbirds). The flowers terminal and lateral; one per areole; tubular; sessile; medium-sized to large; to 5 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel with narrow overlapping scales subtending wool or hairs. The hypanthial tube not naked; with scales. The axils of the scales of the hypanthial tube not naked (subtending wool or hairs). The hypanthial tube spineless. The perianth yellow; limb short or none. The perianth segments more or less erect (unexpanded, the imbricate segments not spreading apically). The androecium without staminodes. Stamens adnate to the perianth (inserted in the throat and tube); and style exserted beyond the perianth.
The mature fruit to 2 cm long (to 3 cm in diameter); reddish; fleshy; without watery and translucent pulp. The seeds small; black; ovoid, or pyriform (?); not encased in bony arils. The testa shiny. Cotyledons reduced or vestigial.
Natural Distribution. Bolivia.
Classification. 1 species (C. chrysocephalus). Subfamily Cactoideae. Tribe Trichocereeae.
Cf. Anderson, 2001.
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’.