Engelmann, Contributions from the United States National Herbarium 13(9): 309, 1911
Opuntia cyclodes is a little-studied plant from NM. It was originally described as a variety of O. engelmannii; however, the two species are visually distinct and intermediates are not found. Cladodes are typically circular. More than half or almost all areoles may have spines; often there is a single long spine sweeping down from the areole that may be accompanied by 1 or 2 smaller spines. The current year’s spines are essentially always yellow but may darken towards the base. O. cyclodes is found irregularly over much of eastern NM, and in the El Paso, TX area as well. The authors have observed O. cyclodes in rocky, mountainous locations (eg, Villanueva State Park, NM) and in flat, sandy areas (eg, Conchas Lake State Park, NM). The type locality is “the upper Pecos” of NM. See the original citation. O. cyclodes may be hexaploid.