Corynopuntia, commonly known as club chollas or perritos (Spanish: "little dogs"), is a genus of opuntioid cacti in the family Cactaceae (order Caryophyllales), native to the desert regions of the southwestern United States and northern Mexico. The genus was first described by Knuth in 1935 as a segregate from Opuntia, and its taxonomic history has been complex: it was reduced to sectional rank, reinstated, and ultimately merged into Grusonia following a 2016 molecular phylogenetic study demonstrating that Corynopuntia and Grusonia were polyphyletic when treated separately. Plants of the World Online accepted this synonymy in June 2021.
Plants in this group form low cushion-like mounds built from somewhat ovoid to club-shaped (clavate) stem segments, typically 1 to 25 cm in length. The segments are tuberculate rather than ribbed, smooth-surfaced (glabrous), and armed with stout, very sharp spines whose margins bear fine denticles and a narrow epidermal sheath (tunica) at the tip. Flowers are typically yellow; a few species produce pink to deep magenta blooms. The fruit is narrowly obconic to ellipsoid, initially fleshy then quickly drying, yellowish to brownish, frequently malodorous, and densely set with glochids and spines.
A particularly notable ecological trait is the ready detachment of stem segments when brushed by a passing animal. The barbed spines grip fur or skin and can transport a segment considerable distances, making epizoochory the primary means of vegetative dispersal. Despite the morphological similarity among species, sympatric club chollas rarely hybridise naturally, implying strong reproductive isolation. Well-known members include Corynopuntia clavata (club cholla) of the Chihuahuan Desert.
Etymology
The name Corynopuntia combines the Greek coryne ("club") with Opuntia, the parent genus, referring to the distinctively club-shaped stem segments that characterise these cacti. In Mexico the plants are colloquially called perritos ("little dogs"), an allusion to the way detached spine-covered segments cling to passing animals as if biting.
Distribution
Corynopuntia species are native to arid regions of the southwestern United States — California, Arizona, Nevada, New Mexico, and Texas — and to the northern Mexican states of Baja California, Baja California Sur, Sonora, Chihuahua, Coahuila, Nuevo León, Durango, Zacatecas, San Luis Potosí, and Tamaulipas. They occur from near sea level up to approximately 2,000 m elevation.
Ecology
Club chollas are plants of exposed desert flats and gentle slopes, growing in full sun or occasionally beneath sparse shrubs. They tolerate sandy, loamy, or gravelly soils in very dry environments. Their most distinctive ecological adaptation is a physical dispersal mechanism: stem segments break off easily on contact and their finely barbed spines grip animal fur or human skin, enabling the plant to spread to new sites sometimes kilometres away.
Taxonomy Notes
Corynopuntia was established as a genus by Knuth (1935), reduced to a section of Opuntia by Benson (1969), and elevated to a subgenus by Bravo (1972). Molecular and seed-morphology studies in the late 1990s and early 2000s supported reinstatement as a full genus, which the Cactaceae Consensus Group accepted in 2006. A 2016 phylogenetic study of tribe Cylindropuntieae found that keeping Corynopuntia and Grusonia separate rendered both polyphyletic; the two were therefore merged under Grusonia, and this treatment is followed by Plants of the World Online (as of June 2021). GBIF currently lists Corynopuntia as an accepted genus name with zero accepted descendants, reflecting a transitional indexing state consistent with the synonymy.
