| | The genera of Cactaceae |
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The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric; to 3 cm in diameter. The plants terrestrial and self supporting, or scrambling; basally much branched; at first erect, or prostrate (later); shrubby. The branches cylindrical; to 200 cm long (at least, in P. sicariguensis); 3 cm in diameter. The stems not segmented; ribbed and grooved. The ribs 3–7; longitudinal; high and narrow. The grooves wide. The plants not conspicuously tuberculate. The areoles not tubercle-associated; distant; borne in longitudinal series; small, brownish simple. The flowering areoles resembling the non-flowering ones. The areoles with spines. The spines clustered; "numerous"; 0.2–3 cm long; stiff; straight; terete (acicular); white to brownish. The mature stems leafless.
Flowering at night. The flowers lateral; one per areole; long funnelform; sessile; large to very large; 15–16 cm long. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel with areoles bearing clusters of small spines. The hypanthial tube ornamented like the pericarpel, rather rigid; not naked; with spines (in clusters). The perianth white. Stamens not grouped.
The mature fruit to 6 cm long; depressed globose to globose; pale yellow; odoriferous, fleshy; indehiscent. The seeds not encased in bony arils; without a mucilage sheath. Cotyledons reduced or vestigial.
Natural Distribution. Brazil (P. brasiliensis) and Venezuela (P. sicariguensis).
Classification. 2 species. Subfamily Cactoideae. Tribe Pachycereeae.
Images. • Pseudoacanthocereus brasiliensis (as Acanthocereus): Britton & Rose (1920).
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’.
