After we had found Dionysia diapensiifolia and some, not very attractive, plants of Dionysia revoluta I went for a walk higher up the mountain the next day. Here, at an altitude of approx. 2600m I found some more Dionysia revoluta. This time the plants were in full flower, some of them being rather large. This species has a more widespread distribution, and there are even some subspieces known. Later during our trip we found some more Dionysia revoluta on Kuh-e Pashmaku, home of Dionysia iranshahrii. Its not a difficult species in cultivation, after some years plants tend to become rather loose and require replacement by propagation.
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 recognized 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
Some other interesting websites:
Greek Mountain Flora
Botanical Garden of the University Tübingen Germany
Gothenburg Botanical Garden Sweden
Utrecht Botanic Gardens Netherlands
Royal Botanic Garden Edinburgh UK
Alpine Garden Society Encyclopaedia