Opuntia pailana Opuntia pailana Opuntia pailana is a species of the genus "Opuntia" in the family Cactaceae. The name "pailana" comes from the sierra de la Paila in the state of Coahuila Mexico where it was discovered. The first description was published by Wilhelm Weingart in 1929 in the book "Monatsschrift der Deutschen Kakteen-Gesellschaft". Band 1, Nummer 9, 1929, S. 167–169. As most of the species of the genus Opuntia, "Opuntia pailana" is a shruby plant with cladodes (leaves racket-shaped) up to one meter high. The cladods are in color blue-green or when getting older green-yellow, 10 to 14 centimeters long and
Opuntia readily between species. This can make classification difficult, yielding a reticulate phylogeny where different species come together in hybridization. Also, not all species listed here may actually belong in this genus, meaning that "Opuntia" is not a monophyletic group. "Opuntia" also has a tendency for polyploidy. The ancestral diploid state was 2n=22, but many species are hexaploid (6n = 66) or octaploid (8n = 88). Chollas, now recognized to belong to the distinct genus "Cylindropuntia", are distinguished by having cylindrical, rather than flattened, stem segments with large barbed spines. The stem joints of several species, notably the jumping cholla ("Cylindropuntia