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.
Forming dense, very hairy cushions which are usually greyish green although some clones are bright, almost mossy green. Leaves narrow-oblong to lanceolate-elliptic, 2-2.5mm long, 0.5mm wide, hairy on both surfaces, being one of the major distinguishing features from D. bryoides. Corolla violet, 5-6mm diameter on 11mm tube, divided into obovate, very slightly emarginate lobes. First discovered in 1974 by M. Iranshahr but only introduced into cultivation in 1998. All collections are from Kuh-e Pashmaku in Bakhtiari Province, Iran where it grows between 2500-3100m on limestone cliffs. It has proven to be one of the more difficult species to grow beyond 10cm in diameter. There are hybrids, both as a seed and pollen parent but these are not widely distributed. Collections in cultivation are SLIZE213, DZ I 00-38, T4Z111, JMM01-28, JLMS02-55. In 2016 there was a further introduction, CIA183-1 near Semirom in Esfahan Province at 2741m.
Reference: ALPINE GARDEN SOCIETY PLANT ENCYCLOPAEDIA