I grow several forms and varieties of O. basilaris. The beavertail cactus is native to the Mojave and Sonoran deserts to about to 6,000 feet. The blue-gray 10inch long pads are shaped like a beaver's tail. Dense clusters of brown glochids are it's main defence.the flowers are hot pink/magenta. The fruits are dry and pearshaped. Mature clumps can get to be two foot tall and three to four foot across.
Here are a couple of patches of Opuntia basilaris var. basilaris I have.