The segment as an organ of growth and dispersal
Stems consist of cylindrical segments with tubercles and areoles producing spines and glochids. Papery spine sheaths are a characteristic trait of many chollas. The persistence of segment junctions differs between species and changes as tissues develop. In C. bigelovii, easy detachment contributes to reproduction, while in tree-like forms of C. imbricata, wood supports perennial branches. [Mylo et al. 2022] [Morankar et al. 2024] [Majure et al. 2019]
The genus in the phylogenetic tree
The 2019 plastid phylogenomics links Cylindropuntia with Grusonia and their shared lineage with Micropuntia. The group's history is associated with North American dry areas, especially the Chihuahuan and Sonoran deserts. Former names in Opuntia remain common in twentieth-century physiological and ecological papers. [Majure et al. 2019] [Nobel 1983]
Flowers, ploidy and clones
A review of research on six species includes diploid plants with bisexual flowers, clonal C. bigelovii and hexaploid, functionally dioecious C. wolfii. In the latter, flowers appear bisexual, but organ fertility is separated among individuals. Genetic data must be related to specific populations, since the importance of cloning and proportions of different cytotypes vary spatially. [Ramadoss et al. 2025] [Ramadoss et al. 2023]
Fruit chains of C. fulgida form through successive flowers developing from areoles of older fruits. Detached fruits can root like stem fragments. Studies of variety mamillata show, however, that terminal segments were the most frequent successful propagules in the field. [Bobich 2005]
Nectar and biological defence
Extrafloral nectaries develop in young areoles of some species. In C. imbricata, their anatomy and the dependence of visiting-ant numbers on soil water were described. In C. echinocarpa, the relationship between ant species, bug pressure and seed number was studied. C. ramosissima was the species lacking such nectaries in this comparison. [Ávila-Argáez et al. 2019] [Braun and Lortie 2025]