Opuntia azurea

Rose, Contributions from the U.S. National Herbarium 12(7): 291, 1909

Holotype; Isotype; Herbarium; Herbarium; Herbarium; Herbarium (O. azurea parva); Herbarium (O. azurea diplopurpurea); Herbarium (Opuntia azurea discolor); Holotype (Opuntia azurea diplopurpurea)

Details

Opuntia azurea is an attractive species related to O. chisosensis and O. macrocentra. A description of O. azurea appears on page 130 of The Cacti of the Trans-Pecos and Adjacent Areas (Powell and Weedin 2004). The cladodes are glaucous blue-green, and areoles are 5/8 of an inch apart. When mature, spines are black, unequal, and up to 1-inch long. Stigmas are pale green. O. azurea is a wide-ranging (into Mexico) and variable species.

Powell and Weedin described five varieties of O. azurea.

aureispina
azurea
discolor
diplopurpurea A.M. Powell & J.F. Weedin
parva A.M. Powell & J.F. Weedin

We include a sixth possible variety here that is undescribed. We provisionally refer to it as O. diplopurpurea casteretti. Perhaps it is only a white-spined version of O. azurea diplopurpurea. Powell and Weedin considered these white-spined plants to be variants of O. macrocentra and nothing more. See the original description. O. azurea is tetraploid or hexaploid.