Caiophora is a very rare and showy hardy perennial with a dense, basal rosette of glaucous, spiny leaves and large, ice- white flower cups (to 3" in diameter) at soil level. This strange-looking plant is relatively easy to cultivate, plant tolerates temperatures to –4 F. Wonderful for borders, rocks and containers. Needs full sun and light and well draining soil. An excellent candidate for outdoor growing for colder climates. Zone 4-8.