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| The genera of Cactaceae |
~ Trichocereus Ritter
The plants cerioid; not ‘low and very compacted’. The stems very spiny; elongate cylindric; 4.5–7 cm in diameter; pseudocephaliate. The plants branched and offsetting; erect, or prostrate to erect (ascending or somewhat sprawling); shrubby, or tree-like; not developing conspicuous trunks; to 1–4 m high (when erect). The stems columnar, or not columnar. The branches resembling the main stem. The main stem remaining dominant, or not remaining dominant; more or less cylindrical. The branches cylindrical; 4.5–7 cm in diameter. The stems not segmented; ribbed and grooved. The ribs 10–21; longitudinal. The grooves wide to deep and narrow. The plants more or less conspicuously tuberculate, or conspicuously tuberculate to not conspicuously tuberculate (the ribs barely notched in L. fulvus). The tubercles connected by the ribs; borne in longitudinal series. The areoles associated with tubercles to not tubercle-associated; distant to closely approximating; borne in longitudinal series; simple. The flowering areoles differing in form from the non-flowering ones (somewhat, the flowering ones larger and with longer hairs). The areoles felted or woolly; with spines. The spines clustered; 11–26; 0.5–5 cm long; with radials and centrals differentiated (the radials shorter). Central spines 3–6. Radial spines 8–20. The spines stiff; straight (acicular). The mature stems leafless.
Flowering at night. The flowers lateral (but borne toward the stem tips); one per areole; tubular; sessile; medium-sized to large; 5–6 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel elongate, with dense wool and bristles. The hypanthial tube stout; not naked; with scales. The axils of the scales of the hypanthial tube not naked (with dense wool and bristles). The hypanthial tube spineless. The perianth white. Stamens adnate to the perianth; not grouped (in a single series).
The mature fruit 2.5–5 cm long; barrel-shaped; in L. fulvus, green; non-fleshy when mature; dehiscent; dehiscing basally. The seeds small; black; pyriform; not encased in bony arils. The testa shiny, or dull; tuberculate. Cotyledons reduced or vestigial.
Natural Distribution. Peru.
Classification. 2 species (L. fulvus, L. rupicola). Subfamily Cactoideae. Tribe Trichocereeae.
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’.