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| The genera of Cactaceae |
Including Cullmannia Distefano, Neoevansia W.T. Marshall, Nyctocereus (A. Berger) Britton & Rose
The plants tap-rooted, cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric; slender, often stick-like; neither cephaliate nor pseudocephaliate. The plants scrambling, or climbing; not producing aerial roots; sparingly branched; prostrate to erect; shrubby (to virgate), or neither shrubby nor tree-like; to 1–4 m high (when semi-erect). The branches cylindrical, or angled; slender. The stems segmented, or not segmented (usually); ribbed and grooved. The ribs 3–60; longitudinal (sometimes wavy); variously conspicuous to slight. The grooves wide. The plants not conspicuously tuberculate. The areoles usually not tubercle-associated; usually conspicuous on the ribs, closely approximating to distant; borne in longitudinal series; simple. The flowering areoles resembling the non-flowering ones. The areoles without glochids; with spines. The spines clustered; 5–18; (0.05–)0.1–4 cm long; with radials and centrals differentiated, or showing little or no difference between radials and centrals (all similar in form, sometimes flattened against the stem and short). Central spines when present, 1–6. Radial spines 2–12. The mature stems leafless.
Flowering at night. The flowers terminal, or lateral (usually); one per areole; funnelform, or salver-shaped, the perianth limb broad; sessile; large to very large; 7–20(–25) cm long; regular to somewhat irregular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium; not naked; with scales; with spines, or spineless. The pericarpel with bristly areoles. The hypanthial tube not rigid, elongate and slender; not S-shaped; not naked; with scales (these small). The axils of the scales of the hypanthial tube not naked (with areoles bearing bristles or spines). The hypanthial tube with spines, or spineless. The perianth white, or red, or pink; limb relatively large. The perianth segments spreading, or spreading and recurved (then the the outer segments recurved); elongate, relatively narrow, or relatively short, broad; pointed, or acuminate. Stamens adnate to the perianth (inserted in the tube and throat); not grouped.
The mature fruit 2–7.5(–9) cm long; apically tapered, ovoid to ellipsoidal, or pyriform; red; not naked (with deciduous clusters of small spines or bristles); with persistent floral remains, or without persistent floral remains; fleshy; indehiscent. The seeds broadly oval, with basal hilum, the testa shiny or sometimes roughened, black; not encased in bony arils; without a mucilage sheath. Cotyledons reduced or vestigial.
Natural Distribution. California and Mexico.
Classification. About 18 species. Subfamily Cactoideae. Tribe Pachycereeae.
Cf. Hunt (1967).
Images. • Peniocereus marianus: © Zoya Akulova (2017). • Peniocereus hirschtianus (as Nyctocereus serpentinus), with Acanthocereus nudiflorus (as Dendrocereus): Britton & Rose (1920). • Peniocereus serpentinus (as Nyctocereus), with Eulychnia iquiquensis and Isolaterocereus dumortieri (as Lemaireocereus): Britton & Rose (1920). • Eulychnia iquiquensis, with Stenocereus dumortieri (as Lemaireocereus) and Peniocereus serpentinus (as Nyctocereus): 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’.
