Echinopsis — 13 species

Echinopsis is a diverse South American cactus genus spanning globular barrel forms and columnar species, from the cheerful Peanut Cactus and Sea Urchin Cactus to the statuesque Echinopsis huascha with its crimson blooms. All prefer intense direct light — a south-facing windowsill or full outdoor sun — and extremely well-draining soil with very infrequent watering; wet soil quickly causes root rot. Toxicity varies across the genus: Echinopsis multiplex (Easter Lily Cactus) is listed as non-toxic by the ASPCA, but not all species are individually assessed. Check each species before buying if you share your home with cats or dogs.