| | The genera of Cactaceae |
Including Ceratistes Labour. (nom. inval.), Chileniopsis Backeb., Chileocactus Fric (nom. inval.), Chileorebutia Fric (nom. inval.), Chiliorebutia Fric (orth. var.), Delaetia Backeb., Dracocactus Y. Itô (nom. inval.), Euporteria Kreuz. & Buining, Hildmannia Kreuz. & Buining, Horridocactus Backeb., Islaya Backeb., Neochilenia Backeb. ex Dölz, Neoporteria Britton & Rose, Neoporteria Backeb., Neotanahashia Y. Itô, Nichelia Bullock (nom. inval.), Pyrrhocactus (A. Berger) A.W.Hill, Rodentiophila F. Ritter ex Backeb., Thelocephala Y. Itô
The plants condensed-cactoid; low and very compacted in their entirety (mostly), or not ‘low and very compacted’. The plants’ appearance dominated by crowded interlacing areolar structures obscuring any tubercles, ribs or furrows, or dominated neither by crowded areolar structures nor by tubercles covering the areoles. The stems spiny (sometimes fiercely so); large, solitary or proliferous, globose, or shortly cylindric to elongate cylindric (then often globose at first); apically depressed, or not apically depressed. The plants terrestrial and self supporting (mostly), or scrambling (sprawling, in Neoporteria), or geophytic; branched (from underground), or unbranched (mostly); erect; solitary (mostly), or clustering; to 0.01–1 m high. The stems not segmented; ribbed and grooved. The ribs 7–30 (or more); longitudinal, or borne spirally to longitudinal (? - often obscured); usually notched between the areoles. The grooves deep and narrow. The plants mostly conspicuously tuberculate. The tubercles variable in form. The tubercles connected by the ribs; borne in longitudinal series. The areoles associated with tubercles (on their tips); closely approximating. The components of adjacent areoles so extensively covering the mature plant body as to obscure any ribs or furrows (usually), or not obscuring details of the plant body. The areoles at least usually borne in longitudinal series; simple; with spines (these very variable, from fierce and acicular to thin and bristle-like). The spines few to many, (3–)8–60; 0.2–5 cm long; with radials and centrals differentiated, or showing little or no difference between radials and centrals (and centrals sometimes lacking). Central spines when present, (0–)1–12(–20); conspicuously forming a cross (rarely), or not forming a cross. Radial spines 3–24(–40). The mature stems leafless.
Flowering during the day (?). The flowers solitary, or aggregated (usually); terminal to lateral (on young or older areoles near the stem tips); one per areole (usually), or more than one per areole (e.g., paired in Nichelia); almost, tubular, or funnelform, or campanulate; sessile; small; 1–5.5 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 numerous). The axils of the scales of the hypanthial tube not naked (with densely matted white hairs). The hypanthial tube with spines (the upper scales often subtending bristly spines), or spineless. The perianth yellow, or red, or pink. The perianth segments elongate, relatively narrow to relatively short, broad; blunt to pointed. Stamens adnate to the perianth (inserted in the throat and tube); not exserted; in groups (in one series, but usually in two groups - i.e., in Neoporteria).
The mature fruit 0.7–5 cm long; not naked (often woolly), or naked (?); without spines; with persistent floral remains; fleshy (‘hollow berries’); often with loose seeds within, dehiscent; dehiscing via basal pores. The seeds 0.7–3 mm long; sometimes without an obvious micropyle, black; compressed; not encased in bony arils; with hilum and micropyle conjunct. The testa dullish; minutely verrucose to rugose, or smooth, without ornamentation. Cotyledons reduced or vestigial.
Natural Distribution. On slopes of the Andes from central Chile into southern Peru and east into northwestern Argentia.
Classification. About 35 species. Subfamily Cactoideae. Tribe Notocacteae.
Cf. Hunt, 1967.
Images. • Eriosyce subgibbosa (as Neoporteria), with Denmoza rhodacantha, Ariocarpus kotschonbeyanus and Pediocactus simpsonii: Britton & Rose (1922). • Eriosyce islayensis (as Malacocarpus), with Parodia mammulosa (as Malacocarpus), Astrophytum myriostigma and Mila caespitosa: Britton & Rose (1922). • Eriosyce sp. (as Neoporteria gerocephala): © Zoya Akulova (2010).
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’.
