Opuntia cacanapa Opuntia cacanapa Opuntia cacanapa is a cactus in the "Opuntia" genus. In the United States it is found on the South Texas Plains in Brewster County and adjacent counties to the southeast. It also occurs in nearby Mexico. The plants are variable in size, but can form shrubby trees from 1 to 2 m tall. They grow intermixed with other shrubs and small trees. The glaucous pads are pale and not dark green. Cladodes are 15 to 20 cm long and may be elliptical, obovate, or even subcircular. The flowers are a rich, canary yellow and have a prominent green
Opuntia readily between species. This can make classification difficult, yielding a reticulate phylogeny where different species come together in hybridization. Also, not all species listed here may actually belong in this genus, meaning that "Opuntia" is not a monophyletic group. "Opuntia" also has a tendency for polyploidy. The ancestral diploid state was 2n=22, but many species are hexaploid (6n = 66) or octaploid (8n = 88). Chollas, now recognized to belong to the distinct genus "Cylindropuntia", are distinguished by having cylindrical, rather than flattened, stem segments with large barbed spines. The stem joints of several species, notably the jumping cholla ("Cylindropuntia