2.
Cylindropuntia
(Engelmann) F. M. Knuth in C. Backeberg and F. M. Knuth, Kaktus-ABC. 410. 1935.
Cholla [Latin
cylindrus
, cylinder, and
Opuntia
, the genus from which this segregate was removed]
Donald J. Pinkava
Opuntia
Miller subg.
Cylindropuntia
Engelmann, Proc. Amer. Acad. Arts 3: 302. 1856;
Opuntia
sect.
Cylindropuntia
(Engelmann) Moran ex H. E. Moore
Trees or shrubs
, rarely forming mats, erect, usually many branched.
Stem segments
firmly attached to easily dislodged, straight to curved, cylindric to slightly clavate, 2-40(-50) × 0.3-5.5 cm, usually glabrous, tuberculate; areoles elliptic, circular, ovate, obovate, or obdeltate to rhombic, 0.7-5 mm diam.; wool white, yellow, or tan to brown.
Spines
with whole epidermis sheath deciduous; major spines not or only basally angularly flattened.
Glochids
usually in tuft at adaxial margin, yellow to brown.
Flowers
bisexual or sometimes functionally pistillate, radially symmetric; outer tepals green with margins tinged color of the inner; inner tepals yellow-green, yellow to bronze, or red to magenta, spatulate, emarginate-apiculate.
Pollen
spinulo-punctate, not reticulate (cylindropuntioid type).
Fruits,
if fleshy, green, yellow, or scarlet, sometimes tinged red to purple or, if dry, tan to brown, cylindric to subspheric, sometimes clavate, fleshy or dry, spineless or spiny; areoles bearing short feltlike wool of various colors, often tan or gray.
Seeds
pale yellow to tan or gray, flattened to subspheric, angular to squarish or circular, often warped, 1.9-7 mm, commonly bearing 1-4 large depressions per side due to pressure from adjacent developing seeds, glabrous; funicular girdle smooth or with low marginal ridge.
x
= 11.
Species ca. 35 (22 in the flora): sw and sc United States, Mexico, West Indies; introduced to South America (Chile, Ecuador, Peru) and South Africa, and widely cultivated.
Interspecific cholla hybrids are known, and many have been named. Only two are fully treated here:
Cylindropuntia
×
kelvinensis,
because it is so widespread, and
C.
×
tetracantha,
because it has been confused with other hybrids. Additional named hybrids are described briefly and cross-referenced under the putative parental taxa entries.
SELECTED REFERENCE
Pinkava, D. J. 1999. Cactaceae cactus family: Part 3.
Cylindropuntia....
J. Arizona-Nevada Acad. Sci. 32: 32-47.
