Stenocactus is a genus of small cacti in the family Cactaceae (order Caryophyllales), native to northern and central Mexico. The genus comprises roughly 10 accepted species and is closely related to Ferocactus. It formerly encompassed plants placed in Echinofossulocactus Britton & Rose and Efossus Orcutt, both of which are now treated as synonyms.
Plants in this genus are typically small, globular to shortly cylindrical cacti, generally under 10 cm (4 in) in diameter. They are highly variable in spine form and number across species. A number of species are popularly known as "wave cacti" or "brain cacti" on account of their unusually large number of undulating, corrugated ribs — a feature rare among cacti. Plants are usually solitary when young but may develop into small clusters with age.
The flowers are short and funnel-shaped, typically less than 2.5 cm (1 in) across, and often marked with a darker median stripe on each petal. Blooming generally occurs in late winter to spring, with individual flowers lasting only a few days. Plants are not always self-fertile, so cross-pollination between unrelated individuals may be required to set seed. Seeds are produced in green pods and germinate readily under cultivation.
Etymology
The name Echinofossulocactus — a former synonym widely used before Stenocactus was reinstated — derives from Latin, meaning roughly "Echinocactus with a little ditch," a reference to the small groove or wrinkle extending from the top of the areola characteristic of some species.
Distribution
Stenocactus is endemic to Mexico, occurring across northern and central regions of the country.
Cultivation
Stenocactus species are propagated easily from seed, which germinates readily. Because plants are not always self-fertile, producing seed in cultivation may require having multiple unrelated individuals flowering simultaneously.
Taxonomy Notes
The genus Stenocactus has a complex nomenclatural history. The name Echinofossulocactus Britton & Rose was long used as the accepted name for these plants; Efossus Orcutt is treated as an orthographic variant. Both are now synonymised under Stenocactus. GBIF recognises 13 infrageneric taxa under this name.
