Autor: (Berger) Riccobono

“Narrow cereus”, referring to the ribs of most species within the genus, which are narrow.
A genus of treelike or shrubby, columnar, erect, pendulous or exceptionally creeping (S. eruca) plants, sometimes forming impenetrable thickets (S. gummosus), usually strongly branched, some species from the base, others irregularly branched, sometimes forming a trunk. Stems sturdy, with ribs often numerous, mostly tuberculate, areoles woolly. Radial spines spread, 1-4 central spines, usually sturdy, sometimes flattened like a dagger.
Flowers usually nocturnal in most species, sometimes remaining open until the next day, rarely diurnal (S. alamosensis), often scented, funnel-shaped or bell-shaped, with scaly and often spiny pericarpel, pollinated at night by bats (Anoura geoffroyi, Antrozous pallidus, Artibeus jamalcensis, Carollia sp, Choeronycteris mexicana, Glossophaga commissarisi, G. leachii, G. longirostris, G. soricina, Leptonycteris curasoae, L nivalis, L. sanborni, L. yerbabuenae, Phyllostomus discolor), in the daytime, by hummingbirds (Amaziiia beryliina, A. rutila, A. violiceps, Archilochus colubris, Caiypte costae, Cynanthus latirostris, C. sordidus, Eugenes fulgens, Lampornis clemenciae, Phaetornis superciliosus, Selasphorus rufus), other birds (Auriparus flaviceps, Colaptes auratus, Icterus gularis, I. pustulatus, Melanerpes aurlfrons, M. hypopolius, M. uropygialis, Toxostoma curvirostre, Zenaida asiatica, Z. macroura), bees (Agapostemon sp., Apis mellifera, Bombus sp., Halictus sp, Melipona sp., Scaptotringona sp., Trigona sp.) and a butterfly (Hamadryas sp.). Fruits globose or egg-shaped, more or less fleshy according to species,usually edible and consumed by the local populations, with deciduous spines when ripe, usually not retaining the remains of the dried perianth. Seeds rather large, obovoid, black, shiny, generally smooth, but also warty, tuberculate or pitted. Dispersal of seeds provided by bats, birds, and also lizards (Sceloporus orcuttii on Stenocereus thurberi, pers. obs.) and small mammals.
Given its great biodiversity, the genus Stenocereus grows in varied habitats, in hot, dry regions and sandbanks, stony deserts and plateaus, in canyons, rocky or sandy hills, on red lavas, at the edge of cliffs, on sandy alluvial plains in the matorral, xerophytic scrub formed by spiny bushes, near coastal areas, from sea level (S. eruca), up to 2120 m in altitude (S. stellatus), together with other cacti (Mammillaria, Pachycereus, Echlnocereus, Corynopuntia, Opuntia) and bromeliads.
Colombia (Boyaca, Cesar, Guajira, Magdalena), Cuba, Guatemala (Baja Verapaz, Chiquimula, El Progreso, Huehuetenango, Jutiapa, Quiche, Zacapa), Mexico (Aguascalientes, Baja California, Campeche, Chiapas, Chihuahua, Colima, Guanajuato, Hidalgo, Guerrero, Jalisco, Mexico D.F., Michoacan, Morelos, Nayarit, Oaxaca, Puebla, Queretaro, San Luis Potosi, Sinaloa, Sonora, Zacatecas), Puerto Rico, Dominican Rep., USA (Arizona, California), Venezuela (Sucre).

Currently 20 recognised species + one subspecies:
– Stenocereus alamosensis* (J. Coulter) Gibson & Horak 1979 (ex Rathbunia)
– Stenocereus beneckei* (Ehrenb.) Buxb. 1961 (ex Hertrichocereus)
– Stenocereus chacalapensis* (Bravo & Macdoug.) Buxb. 1961
– Stenocereus chrysocarpus* Sanchez-Mejorada 1972
– Stenocereus eruca* (Brandegee) A.Gibson & Horak 1979 (ex Machaerocereus)
– Stenocereus fimbriatus (Lam.) Lourteig 1991 (ex S. hystrix)
– Stenocereus fricii* Sanchez-Mejorada 1973□ Stenocereus griseus* (Haworth) Buxbaum 1961
– Stenocereus gummosus* (K.Brandegee) A.C.Gibson & K.E.Horak 1978 (ex Machaerocereus)
– Stenocereus humilis (Britton & Rose) D.R. Hunt 2002
– Stenocereus kerberi* (K.Schum.) A.C.Gibson & K.E.Horak 1978 (ex Rathbunia)
– Stenocereus martinezii* (J.G. Ortega) Buxbaum 1961
– Stenocereus montanus* (Britton & Rose) Buxbaum 1961
– Stenocereus pruinosus* (Otto) Buxb. 1961
– Stenocereus queretaroensis* (F.A.C. Weber ex Mathsson) Buxbaum 1961
– Stenocereus quevedonis* (J.G.Ortega) Buxb. 1961
– Stenocereus standleyi* (j.G.Ortega) Buxb. 1961
– Stenocereus stellatus* (Pfeiffer) Riccobono 1909
– Stenocereus thurberi* (Engelmann) Buxbaum 1961
– Stenocereus thurberi subsp. littoralis (K.Brandegee) N.P.Taylor 1998
– Stenocereus treleasei* (Britton & Rose) Backeb. 1960

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)