Small, Journal of the New York Botanical Garden 20: 26, 1919
(Also Opuntia mesacantha Raf ssp. lata [Small] Majure)
Opuntia lata is known from central Georgia to northern Florida where it occurs in grassy areas and other openings in pinelands. O. lata forms a prostrate plant that may branch in all directions. Although prostrate, the last cladode on a branch may tend upwards. Cladodes are elliptic or sometimes narrowly obovate and up to 6-inches long; they are often be scalloped (sometimes lightly) in outline. Plants can form irregular mats 3-ft across or more. Spines are delicate (0.7-0.9 mm in diameter). The type specimen was collected near Gainesville, FL. A new taxonomic position as a subspecies of O. mescacantha has been proposed (Opuntia mesacantha Raf ssp. lata (Small) Majure). See the original description. O. lata essentially identical in the field with O. mesacantha. However, O. mesacantha is tetraploid, whereas O. lata is a diploid. Adanick et al., 2018 developed a method to measure stomates (size and distance from each other) in the field and differentiate the two taxa easily.