Opuntia — 15 species

Opuntia is a large genus of flat-padded prickly pear cacti ranging from the ornamental Bunny Ears Cactus to the sprawling Santa Rita and Plains Prickly Pear. All species demand full, direct sun and extremely well-draining soil, and they are remarkably drought-tolerant — water every two to three weeks in the growing season and cut back to near-zero in winter. Toxicity varies across Opuntia species, so check each one individually before buying if you share your home with cats or dogs; even non-toxic varieties carry barbed glochids that can physically injure curious pets.