Opuntia humifusa late spring. The juicy and edible red fruits measure from 3–5 cm. As the fruit matures, it changes colour from green to red, and often remains on the cactus until the following spring. There are 6 to 33 small, flat, light-colored seeds in each fruit. This species was originally native to arid areas of Montana southward to New Mexico, and eastward to the lower Great Lakes, and along the East Coast from the Florida Keys to coastal Connecticut. Some botanists treat this cactus as a variety of "Opuntia compressa": hence "Opuntia compressa" var. "humifusa", or a synonym of "Opuntia compressa".
Opuntia pinkavae magenta anthers and white styles. Fruits are tan, up to 3 cm (1.2 inches) long, dry when ripe. There is a bit of confusion concerning the correct scientific name. Specimens of "O. pinkavae" were distributed for years labeled as ""Opuntia kaibabensis"", a name that was never validly published. Parfitt's original description coining the name "Opuntia pinkavae" and the treatment attributed to Pinkava in Flora of North America suggest that the name was offered as a replacement for another allegedly unpublished name, "Opuntia basilaris" var. "woodburyi". However, the varietal name was indeed validly published, but chromosomal comparisons between it and "O.