| | The genera of Cactaceae |
The plants succulent; cerioid; not ‘low and very compacted’. The stems spiny. The plants branched; erect; massive, tree-like; with well formed trunks (the thick trunks bearing numerous erect or somewhat arching branches); to 5–8 m high. The branches differing in form from the main stem (thinner than the trunk). The main stem remaining dominant; more or less cylindrical. The branches cylindrical; 9–10 cm in diameter. The stems usually not segmented; ribbed and grooved. The ribs 8–9; longitudinal. The grooves wide to deep and narrow. The plants not conspicuously tuberculate. The areoles not tubercle-associated; distant; borne in longitudinal series; simple. The flowering areoles resembling the non-flowering ones (?). The areoles with spines. The spines clustered; 8–10; about 1–5 cm long; with radials and centrals differentiated (the central, erect one to 5 cm long, the spreading radials to 3 cm long). Central spines 1. Radial spines 7–9. The spines heavy, stiff; straight; terete; yellow, blackening. The mature stems leafless.
Flowering at night, or at night and during the day. The flowers lateral; one per areole; funnelform; sessile; large; to 15 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel with scales. The hypanthial tube elongate; not naked; with scales (these numerous, broad, imbricate). The axils of the scales of the hypanthial tube more or less naked. The hypanthial tube spineless. The perianth pale pink, or white; limb relatively large. The perianth segments relatively short, broad; blunt to pointed. Stamens adnate to the perianth (inserted in the tube).
The mature fruit ovoid; green, or red (-ish); not naked (with numerous scales); without persistent floral remains; fleshy (edible); indehiscent (?). The seeds with a broad lateral hilum, brown; curved- reniform (in outline); curved; not encased in bony arils; with hilum and micropyle conjunct. Cotyledons reduced or vestigial.
Natural Distribution. High arid northwestern Argentina, Bolivia and Paraguay.
Classification. 1 species (S. coryne). Subfamily Cactoideae. Tribe Browningieae.
Cf. Hunt (1967).
Images. • Stetsonia coryne: Britton & Rose (1920). • Stetsonia coryne: © 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’.
