| | The genera of Cactaceae |
~ Disocactus, cf. Hunt (1967)
The plants cerioid; not ‘low and very compacted’. The stems not spiny. The plants epiphytic, or lithophytic; producing aerial roots; much branched (with the initially cylindrical stems becoming flattened); with cladodes (these obtusely toothed). The cladodes with midribs to without midribs. The plants erect (with arching stems); shrubby. The branches basally pedunculate, distally flattened; 0.2–6 cm wide. The stems segmented; annually articulating; not ribbed and grooved. The plants more or less conspicuously tuberculate. The tubercles in the form of marginal notches. The tubercles borne along the margins of the flattened branches. The areoles associated with tubercles (i.e., in the marginal notches); distant; borne along the margins of the flattened branches; simple. The flowering areoles resembling the non-flowering ones. The areoles woolly (with short, greyish wool); without bristles; without glochids; without spines. The mature stems leafless.
Flowering during the day. The flowers lateral, or terminal and lateral; one per areole (but numerous); shortly funnelform, or rotate; sessile; 0.7–3.5 cm long. The receptacle not naked; with scales; spineless. The pericarpel with a few small scales. The hypanthial tube not naked; with scales (these few, small); spineless. The perianth sequentially intergrading from sepals to petals, or of ‘tepals’; sometimes with united segments; green (-ish), or white, or white and purple. Stamens exserted beyond the perianth. Gynoecium inferior (with a few small scales).
The mature fruit 0.4–1.1 cm long; globose to ovoid; white, or purple (tinged); "more or less" naked; without spines; fleshy; indehiscent (?). The seeds dark brown; ovoid; not encased in bony arils; with hilum and micropyle fused; with a mucilage sheath. The testa pitted, or smooth, without ornamentation. Cotyledons reduced or vestigial.
Natural Distribution. Central America and Caribbean, with one in South America.
Classification. 6 species. Subfamily Cactoideae. Tribe Hylocereeae.
Images. • Pseudorhipsalis amazonica (as Wittia panamensis): Bot. Mag. 145 (1919). • Pseudorhipsalis alata, P. himantoclada and P. ramulosa (as jamaicensis), with Lepismium ianthothele (as Pfeiffera) and L. cruciforme: Britton & Rose (1923). • Pseudorhipsalis ramulosa (as R. coriacea), with Rhipsalis dissimilis, R. teres (as heteroclada and prismatica) and ‘R. biformis = ?: 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’.
