I love the named of this one: Blind Prickly Pear. It's not quite pettable but it is missing those sharp spines. Wiki says: native to southwestern Texas and northern Mexico, where it grows on rocky slopes. The species makes up for its total lack of spines with a profusion of red-brown glochids. The common name blind prickly pear or cow blinder comes from the fact that the glochids may be carried away by the wind and blind animals.