Eastern prickly pear cacti (Opuntia humifusa) to be more specific. One of my favorite native plants, this little beauty is definitely one of the stars of the south-facing border in our front yard. See here for a Plant Care Profile I did for this species.
Eastern prickly pear cactus (Opuntia humifusa)
Encouraged by the success I have been having with this plant, I recently added another species of cactus to our garden. The pineapple cactus (Coryphantha sulcata), also known somewhat more awkwardly as nipple cactus, is supposedly hardy to Zone 5 and produces pale yellow flowers on rounded little plants.