Opuntia also native to sandy coastal beach scrub environments of the East Coast from Florida to southern Connecticut ("Opuntia humifusa"). "Opuntia" species are the most cold-tolerant of the lowland cacti, extending into western and southern Canada; one subspecies, "O. fragilis" var. "fragilis", has been found growing along the Beatton River in central British Columbia, southwest of Cecil Lake at 56° 17’ N latitude and 120° 39’ W longitude. Prickly pears also produce a fruit, commonly eaten in Mexico and in the Mediterranean region, known as "tuna"; it also is used to make "aguas frescas". The fruit can be red, wine-red, green,
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