| | The genera of Cactaceae |
Including Buiningia Buxb.
The plants cerioid; low and very compacted in their entirety, or low and very compacted in their entirety to not ‘low and very compacted’ (C. purpureus). The stems spiny; globose to ovoid, or shortly cylindric, or elongate cylindric; cephaliate to pseudocephaliate (the cephalia continuous, more or less sunken in the stems on reduced and depressed ribs). The plants terrestrial and self supporting, or scrambling (or crawling); basally branched, or unbranched; prostrate, or erect; neither shrubby nor tree-like, or shrubby; to 0.2–5 m high. The stems columnar, or not columnar. The main stem globose to ovoid, or more or less cylindrical. The branches cylindrical. The stems segmented, or not segmented; ribbed and grooved. The ribs 6–35; longitudinal; rounded. The grooves wide. The plants not conspicuously tuberculate. The areoles not tubercle-associated; closely approximating; borne in longitudinal series; simple. The flowering areoles differing in form from the non-flowering ones (with white wool and long, sturdy bristles). The areoles with spines. The spines 5–27; 0.5–11 cm long; with radials and centrals differentiated. Central spines (0–)1–9. Radial spines 4–19. The spines stiff, or flexible (weak or strong, flexible); straight; variously coloured. The mature stems leafless.
Flowering at night. The flowers terminal, or lateral, or terminal and lateral; one per areole; tubular, or funnelform, or campanulate; sessile; small to large; 2–8 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel small, naked or with a few small scales. The hypanthial tube long, naked or with a few small scales; naked, or not naked; with scales (these small), or without scales; spineless. The perianth green, or white to yellow, or red, or pink, or purple.
The mature fruit 1.6–3.5 cm long; globose, or ovoid, or ellipsoidal, or clavate; red to purple; naked; smooth, fleshy; dehiscent; dehiscing via basal pores. The seeds about 1 mm long; black; globose or sub-globose, or ovoid, or pyriform; not encased in bony arils; with hilum and micropyle conjunct. The testa tuberculate. Cotyledons reduced or vestigial.
Natural Distribution. Brazil.
Classification. 6 species. Subfamily Cactoideae. Tribe Cereeae.
Images. • Coleocephalocereus fluminensis (as Cephalocereus): Britton & Rose (1920). • Fruit of C. fluminensis: 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’.
