|This group of flowering cactus is native to the Southwestern United States, Central, Eastern and Northern Mexico. The body of the cactus is round and squat and may have ribs or warts, depending on the species. Diurnal flowers are showy, large, funnel-shaped, and grow from depressions on the crown. The thelocactus species are often grown as houseplants. Soil should be gritty and well-drained. If growing one of the thelocactus species, do so in a commercial cactus potting mix. From midspring to early fall, water moderately, but keep dry during the remainder of the year. During the growing season, fertilize 2 or 3 times with a water soluble fertilizer. May divide and replant or repot offsets in early summer.