Opuntia robusta Opuntia robusta Opuntia robusta, the wheel cactus, nopal tapon, or camuesa, is a species of cactus in the Cactaceae family. It is native and endemic to central and northern Mexico to within 100 miles of the Arizona and New Mexico borders where it grow from 5,000 to 10,000 feet on rocky slopes, open shrub lands, woodlands and mixed with other cactus and succulents. Plants are commonly around high, though they may grow to over high when supported. The flattened stem segments are fleshy, round and blue-grey in colour. These are up to in diameter and have sharp spines up to
Opuntia pinkavae magenta anthers and white styles. Fruits are tan, up to 3 cm (1.2 inches) long, dry when ripe. There is a bit of confusion concerning the correct scientific name. Specimens of "O. pinkavae" were distributed for years labeled as ""Opuntia kaibabensis"", a name that was never validly published. Parfitt's original description coining the name "Opuntia pinkavae" and the treatment attributed to Pinkava in Flora of North America suggest that the name was offered as a replacement for another allegedly unpublished name, "Opuntia basilaris" var. "woodburyi". However, the varietal name was indeed validly published, but chromosomal comparisons between it and "O.