| | The genera of Cactaceae |
Including Diploperianthium F. Ritter (nom. inval.)
The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric. The plants not producing aerial roots; densely branched (forming numerous ascending branches); erect; shrubby, or tree-like; to 8 m high. The main stem more or less cylindrical. The branches cylindrical and angled; to 100 cm long. The stems segmented; annually articulating; thinly 3–4 ribbed and grooved (or winged). The ribs longitudinal. The plants more or less conspicuously tuberculate (the ribs conspicuously notched). The tubercles connected by the ribs; borne in longitudinal series. The areoles associated with tubercles; borne in longitudinal series (in the notches); simple (3–6 mm in diameter); with spines. The spines clustered; 1–5 cm long (centrals), or 0.5–1 cm long (radials); with radials and centrals differentiated. Central spines strong, 1–6. Radial spines more or less erect, 3–8. The spines stiff; straight; terete (acicular). The mature stems leafless.
Flowering at night. The flowers lateral; more than one per areole; narrow, tubular to funnelform; sessile; large; 9.5–11 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel ornamented like the tube. The hypanthial tube not naked; with scales (these small). The axils of the scales of the hypanthial tube not naked (with felted areoles and spines). The hypanthial tube with spines (these bristly). The perianth obscured by the tube during bud development; segments numerous; white and brown (the inner members white, the outer members reddish brown). The perianth segments spreading (over the tubes, at maturity). Stamens very numerous; adnate to the perianth (inserted in the throat and tube, the lowermost on a slight ridge partially covering the deep nectar chamber).
The mature fruit ovoid to ellipsoidal (ovoid-cylindric, somewhat 4-angled); light green; not naked (with scattered areoles); fleshy; indehiscent. The seeds few, obovate with basal hilum, black (-ish); not encased in bony arils. The testa verrucose. Cotyledons reduced or vestigial.
Natural Distribution. Northern Peru.
Classification. 1 species (C. substerile). Subfamily Cactoideae. Tribe Calymmantheae.
Cf. Hunt, 1967.
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’.