The green stems of this low-growing perennial cactus are flattened, and are formed of segments. Barbed bristles are found around the surfaces of the segments, and longer spines are sometimes present.

This plant is very intolerant of shade and instead thrives in sunny, hot and dry environments with well-draining, sandy soil. Opuntia humifusa will grow in open areas in sandy, rocky and coastal scrub habits. They are capable of surviving cool winters unlike many cacti, although harsh winter storms are known to cause habitat loss.