|
| The genera of Cactaceae |
Cardón.
Including Backebergia Bravo, , Lemaireocereus Britton & Rose, Lophocereus (A. Berger) Britton & Rose, Marginatocereus (Backeb.) Backeb., Mitrocereus (Backeb.) Backeb., Pterocereus T.MacDoug. & Miranda
The plants cerioid; not ‘low and very compacted’. The stems spiny; elongate cylindric; cephaliate, or pseudocephaliate, or neither cephaliate nor pseudocephaliate. The plants terrestrial and self supporting; branched; erect; shrubby, or tree-like (sometimes candelabra-like, often becoming massive); with well formed trunks (sometimes), or not developing conspicuous trunks; solitary (mostly), or clustering; to 1.5–25 m high. The stems columnar. The branches resembling the main stem. The main stem more or less cylindrical. The branches cylindrical. The stems mostly not segmented; ribbed and grooved. The ribs 3–16; longitudinal. The grooves wide. The plants not conspicuously tuberculate. The areoles not tubercle-associated; closely approximating, or confluent. The confluent areoles lateral. The areoles borne in longitudinal series; simple. The flowering areoles differing in form from the non-flowering ones, or resembling the non-flowering ones (the non-flowering ones spiny, the flowering ones sometimes spineless, but with dense wool and long bristles, confluent or connected by furrows). The areoles without glochids; or at least the sterile ones with spines. The spines clustered; 7–32; 0.2–10 cm long; with radials and centrals differentiated (with the 1–4 stout centrals and 20 or more somewhat shorter radials), or showing little or no difference between radials and centrals. Central spines when differentiated, 1–4. Radial spines (3–)9–30. The spines straight; terete. The mature stems leafless.
Flowering during the day, or at night (Lophocereus), or at night and during the day (lasting two days in P. orcuttii). The flowers terminal, or lateral, or terminal and lateral; one per areole, or more than one per areole (Lophocereus); shortly tubular, or funnelform, or campanulate; sessile; medium-sized to large; 4–10 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The pericarpel scaly, with areoles naked or woolly or bristly. The hypanthial tube stout; not naked; with scales. The axils of the scales of the hypanthial tube more or less naked, or not naked (then with woolly or bristly areoles). The hypanthial tube spineless. The perianth exposed during bud development; white, or yellow, or orange, or pink, or purple; limb relatively large. The perianth segments relatively short, broad. Stamens very numerous, up to 3,482 in a flower recorded by Bessy in 1914!; adnate to the perianth (inserted in the tube and throat).
The mature fruit (1–)2.5–8 cm long; ellipsoidal; red, or red to purple; not naked (densely covered with wool and bristles and sometimes a few short spines); spiny, or without spines; becoming non-fleshy when mature; dehiscent, or dehiscent to indehiscent; irregularly dehiscent. The seeds numerous, large, with a truncate hilum, black; pyriform, or helmet- or hat-shaped ("obovate or helmet shaped); not encased in bony arils; without a mucilage sheath. The testa shiny, or dull; smooth, without ornamentation. Cotyledons reduced or vestigial.
Natural Distribution. Southwestern United States, northern Mexico, Honduras and Guatemala.
Classification. 11 species. Subfamily Cactoideae. Tribe Pachycereeae.
Cf. Hunt (1967).
Images. • Pachycereus marginatus: © Zoya Akulova (2016). • Pachycereus marginatus: © Zoya Akulova (2015). • Pachycereus marginatus: © Zoya Akulova (2016). • P. militaris (as chrysomallus): 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’.
