DNA research has revealed the close relationships of various taxa now grouped in this genus previously classified as Grusonia, Micropuntia, or just plain Opuntia. The species offered here was originally named Opuntia marenae, then placed by Backeberg in his monotypic Marenopuntia. It differs from other species with more club-shaped joints in its slender, graceful stems, which led to a tentative initial identification in 1932 by NL Britton of Wilcoxia (now considered a slender-stemmed section of Echinocereus) based on vegetative material. However, the species shares the flattened central spines of other corynopuntias, as well as the opuntioid flowers, in this case satiny-yellow in color. Once it had flowered it in cultivation, Sidney Parsons named the species Opuntia marenae after Maren B Parsons, who first found the plant near their campsite at the mouth of the Río Bacuachic in May, 1910. Also in common with some species of Wilcoxia are the tuberous roots, which in C. marenae can develop into a convoluted caudex with time. The species is restricted to the vicinity of Kino Bay in the northern Mexican state of Sonora. Rooted cuts of HBG 92967, a plant received from Seymour Linden in 1984. $8.
Published in the Cactus and Succulent Journal, Vol. 81 (2), March - April, 2009