| | The genera of Cactaceae |
~ Escobaria
The plants condensed-cactoid; low and very compacted in their entirety. The plants’ appearance dominated by crowded interlacing areolar structures obscuring any tubercles, ribs or furrows (A. roseana), or dominated neither by crowded areolar structures nor by tubercles covering the areoles (A. aguirreana). The stems spiny; globose to shortly cylindric. The plants erect; solitary (usually), or clustering; to 0.04–0.06 m high. The stems not segmented; ribbed and grooved. The ribs numerous; borne spirally; largely comprising tubercles. The grooves deep and narrow. The plants very conspicuously tuberculate. The tubercles fleshy, 3–5 mm long. The tubercles connected by the ribs; spirally disposed. The areoles associated with tubercles. The components of adjacent areoles so extensively covering the mature plant body as to obscure any ribs or furrows (A. roseana), or not obscuring details of the plant body. The areoles born on the tubercle tips, spirally disposed; simple; with spines. The spines numerous clustered; 15–40; 0.8–2 cm long; with radials and centrals differentiated (somewhat), or showing little or no difference between radials and centrals. Central spines 2–6(–12). Radial spines sometimes in two series, 13–30. The spines straight to curved. The mature stems leafless.
The flowers solitary, or aggregated; terminal; sessile; small to medium-sized; 1.5–2 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The hypanthial tube short. The perianth not ciliate, cream, or yellow, or pink (or reddish yellow). The perianth segments fairly relatively short, broad; apiculate.
The mature fruit about 8–12 cm long; clavate; green, or purplish bronze. The seeds not encased in bony arils. Cotyledons reduced or vestigial.
Natural Distribution. Mexico.
Classification. 3 species. Subfamily Cactoideae. Tribe Cacteae.
Images. • Acharagma aguirreana: © Zoya Akulova (2007).
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’.
