4-6" x 3-4" wide. (Seed propagated). This species is renowned for its extremely tight, polished spines, attractive banded stems and huge pink flowers! The Peloncillo Mts. collection typically develops bright reddish-pink and white spines giving its stems very colorful banding as they mature. Stems are usually solitary. This species can be very challenging to grow in outdoor beds when conditions are not like those of its southwestern US habitat. It demands perfect drainage, a searing hot planting location and very dry winter conditions. This is a challenging plant to grow but the rewards are sweet if you can find the right spot for it. Zones 7-10. *ECHINOCEREUS rigidissimus:* A jewel of the Sonoran Desert, this species has a tight lattice of tiny spines that hide the body of the plant. Each year's growth is differentiated by differently colored band of spines, hense the common name Arizona Rainbow. The huge 3 to 4 inch wide blooms are bright pink. Not hard to grow in a clay pot, but only recommended for experienced cactus gardeners when grown outdoors. Nice companion plants for Epithelantha micromeris. 3" deep Standard pot.