Laxly branched subshrub generally forming laxer, more uneven tufts that become noticeably bare and woody below with age. Leaf margin with 6-8 pairs of small blunt teeth. Flowers often 2-4 per rosette, sessile, the limb of the corolla slightly larger, 10-12mm diameter. Widespread in the Zagros mountains of Iran, typically growing on shady limestone cliffs, particularly beneath overhangs, 1800-3000m. Fairly readily propagated from cuttings and since the turn of the century there have been a considerable number of introductions leading to various seed raised plants. Two subspecies, ssp. revoluta and ssp. canescens have been recognised for several decades although the differences are minor and some authorities question their status. Ssp. revoluta is represented by H1949, T4Z030, T4Z070, T4Z080, T4Z095, T4Z119, T4Z1042, DZ I 00-43, DZ I 00-44, DZ I 00-45, DZ I 01-08, SLIZE252, JLMS02-99, JMM01-17, JMM01-38, JMM01-44, JMM01-76. Ssp. canescens, H1980, JLMS02-42, SLIZE192, SLIZE196, SLIZE240, JZZ05-170. Indeterminate subspecies KUHI262-1, KUHI265-1, CIA165, CIA186, CIA214, CIA229.
Reference: ALPINE GARDEN SOCIETY PLANT ENCYCLOPAEDIA