| | The genera of Cactaceae |
Foxtail cactus, Pincushion cactus.
Including Cochiseia W.H. Earle, Escobesseya Heter, Fobea Fric (nom. inval.), Neobesseya Britton & Rose
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, or dominated neither by crowded areolar structures nor by tubercles covering the areoles. The stems spiny; discoid, or globose, or shortly cylindric; not apically depressed. The plants branched, or unbranched, or offsetting; erect; solitary, or clustering; to 0.01–0.25 m high. The stems columnar, or not columnar. The stems not segmented; not ribbed and grooved. The plants conspicuously tuberculate. The tubercles terete, often becoming corky and deciduous with age; longitudinally grooved adaxially from the areole towards their ‘axils’. The tubercular groove extending more than halfway to the ‘axil’. The tubercles not connected by ribs; spirally disposed, or borne in longitudinal series. The areoles associated with tubercles; closely approximating, or distant. The components of adjacent areoles so extensively covering the mature plant body as to obscure any ribs or furrows, or not obscuring details of the plant body. The areoles spirally disposed, or borne in longitudinal series. The morphologically geminate, super-imposed buds separated, with the lower one in the axil of the conspicuous tubercle that bears the upper one at its tip. The areoles with the abaxial spine cluster at the tubercle tip connected to the adaxial floriferous meristem nearer its axil by a recessed linear isthmus or a ridge (the groove extending from the tubercle tip to its axil); associated with extra-floral nectaries (rarely, in the groove), or not associated with extra-floral nectaries; with spines. The spines clustered (usually numerous, densely covering the plant); (10–)20–75; 0.3–1.5(–2.5) cm long; with radials and centrals differentiated (usually but not always with the outer radiating and the inner porrect), or showing little or no difference between radials and centrals (or centrals may be lacking). Central spines (0–)1–22. Radial spines 10–50. The spines usually short, fine; usually straight. The mature stems leafless.
The flowers sub- terminal to lateral (arising in the axils of nascent tubercles at the distal ends of the areolar grooves); one per areole; erect, campanulate (but often not fully opening); sessile; small to medium-sized; 2–7 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium to scarcely produced beyond the ovary. The pericarpel naked or with a few small scales. The hypanthial tube naked, or not naked; with scales (a few, these small), or without scales. The axils of the scales of the hypanthial tube more or less naked. The hypanthial tube spineless. The perianth having the outer and rarely the inner segments ciliate; nearly always red, or pink, or purple (but pale yellow, olive green or whitish with pinkish midveins in E. zilziana). The perianth segments elongate, relatively narrow to relatively short, broad; pointed. Stamens adnate to the perianth (inserted in the tube, the filaments clustered around the style and sometimes spiralled).
The mature fruit 0.5–2.5 cm long; globose, or ovoid, or ellipsoidal; red (usually), or green, or pink; usually naked; with persistent floral remains; initially fleshy. The seeds 1–1.7 mm long; blackish brown, or black; reniform or broadly oval to almost circular; not encased in bony arils. The testa regularly and deeply, minutely pitted. Cotyledons reduced or vestigial.
Natural Distribution. Southern Canada south throughout the western United States and into northern Mexico, with only E. cubensis in Cuba.
Classification. About 24 species. Subfamily Cactoideae. Tribe Cacteae.
Cf. Hunt, 1967.
Images. • Escobaria cubensis (as Coryphantha), E. vivipara (as Coryphantha arizonica) and E. deserti (as Coryphantha chlorantha), with Coryphantha durangensis, C. bumamma (as elephantidens), Neomammillaria confusa and N. geminispina: Britton & Rose (1923). • Escobaria dasycantha and E. emskoetteriana (as bella), with Mammillaria sphaerica (as Dolichothele), Mammillaria schumannii (as Bartschella), Neomammillaria carnea, Neomammillaria crocidata, and ‘Neomammillaria arida’ (cf. Mammillaria petrophile): Britton & Rose (1923). • Escobaria missouriensis (as Neomammillaria), with Mammillaria magnimamma, M. karwinskiana and M. gigantea (all as Neomammillaria): Britton & Rose (1923).
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’.
