Prickly pears typically grow with flat, rounded cladodes (also called platyclades) armed with two kinds of spines; large, smooth, fixed spines and small, hairlike prickles called glochids, that easily penetrate skin and detach from the plant.
Chollas, now recognized to belong to the distinct genus Cylindropuntia, are distinguished by having cylindrical, rather than flattened, stem segments with large barbed spines.