Etymology - The Greek opsis refers to appearance and thus the name infers "Maihuenia-like".
By default, there are listed 19 species under the genus Maihueniopsis. All but one of these is recognized by Anderson while The New Cactus Lexicon lists only 7 species placing two in Tephrocactus and the rest listed as synonyms of M. glomerata. As with most Opuntiads, this discrepancy is not surprising because of the wide range of variation from plant to plant. No doubt as more studies are made, further reclassification will occur.
Maihueniopsis plants form cushions on the ground of tightly-packed stem-segments. Stems are mostly round or globular and several species have large taproots with very little growth above ground. Unlike Maihuenia, the leaves of Maihueniopsis fall away as the new growth matures. Spines may be long and dense, protecting the plants or tiny and tight against the stem. Flowers are mostly yellow, rarely white or red.
In habitat, the distribution of this genus is fairly widespread from Peru down through Chile and into Argentina and Bolivia. Plants may be found at high elevation where UV radiation is especially strong and temperatures swing drastically from freezing to well above freezing in just one day. Among cactus-enthusiasts, many of the species are readily found in cultivation, but are not found in non-specialist nurseries. In general, these species are not difficult to grow, but their shabby appearance and unorthodox growth habit limits them to more eccentric cactus growers.