Systematic notes and a detailed description of Opuntia ficus-indica (L.) Mill. (Cactaceae)

Opuntia ficus-indica is the cactus species with the highest economic importance worldwide. It is cultivated for its fruits, forage, or as host of the cochineal insect, but only in Mexico their young cladodes are consumed as vegetables. The main goals of this study were: a) to integrate systematic notes about its common nomenclature, origin, reproductive biology and ploidy levels of O. ficus-indica; b) to present a complete botanical description based on specimens collected in north-central Mexico; c) to discuss the taxonomical relationships with other Opuntia species to which it has been associated. This cactus is native of Mexico, where the highest cultivar richness is found. From a cytogenetic standpoint, specimens with varying ploidy levels have been identified and reproduction is sexual and propagate asexually, the latter being the most extensively used for cultivating. Samples from 72 different cultivars were collected from 17 locations across eight Mexican States. There seems to be evidence to support the fact that O. ficus-indica is a different species from O. amyclae, O. megacantha and O. streptacantha.