Cylindropuntia tunicata is Texan species that is suitable for open ground culture here in Bay Area. This is moderately frost-hardy plant that tolerates wet winters well.
The plant in my picture grows at Stanford Arizona Garden. It forms nice dense low bushes there, with tight pure-white spines.
Spines of 'true' Cylindropuntias bear thin paper-like sheath, easily detachable. That gives this species the 'tunicata' name. The plant is easy and vigorous in culture but needs extreme care when handled, due to int spines, not only long and sharp but also barbed, with harpoon-like back-pointing micro-teeth.