This variety of Engelmann’s prickly pear, sometimes called tuna cactus, is native to North American deserts, at elevations between 1000-4500' (304-1371 m).
Identification: 4-6' (1.2-1.8 m) high, in clumps up to 15' (4.6 m) wide. Thick
pads are oval or rounded. Flowers are yellow to red. Fruit is barrel-shaped, with very short spines
or no spines. I couldn’t find significant differences between this variety and Engelmann Prickly Pear. See this Opuntia comparison table.
From Britton, Nathaniel Lord, Rose, J. N., The Cactaceae: Descriptions and Illustrations of Plants of the Cactus Family, Press of Gibson Brothers, 1919, p. Vol I, p 114.