The genus Dionysia, belonging in Primula sensu lato, is a typically Irano-Turanian genus almost restricted to the rather dry mountains of the Flora Iranica area, from SE Anatolia and W Iran to Tadzhikistan and Afghanistan. Most species are cushion forming chasmophytes in spring completely smothered in yellow, purple, violet or pink flowers but some are more lax and Primula looking. Some species are very choosy about their habitat and only grow below overhangs, whereas other species can be found also on slightly sloping rocks. In spite of being difficult to grow, a large number of species are cultivated by devoted specialists or in botanical gardens.
When Per Wendelbo (1961) revised the genus Dionysia, he recognised 28 species, but added several more in later publications. 41 species were known to science when Christopher Grey-Wilson (1989) published his semi-popular account The genus Dionysia, in which all species are described and illustrations (including several colour photographs) and distribution maps are provided. The number of recognised species in the present paper is 49 and there is every reason to suspect that there are even more species waiting to be discovered, as several are known from a single locality and/or based on very recent finds.
The number of species in cultivation has also increased dramatically in recent years, from a handful in the 1960s, to an estimated 21 in 1989, when Grey-Wilson wrote his book. Today 44 species are grown, representing 90 % of the known taxa. As live plants are indispensable for a proper understanding of morphology and biology, plants in cultivation have contributed considerably to current progress in our knowledge of the cushion primroses.
Molecular investigations by Ida Trift & al. (2004) have given us a far better understanding of evolution and biogeography of Dionysia. Recent field expeditions have brought us important observations on their habitat and many informative photographs of flowering individuals in the wild.
Several species are considered threatened by nature conservation authorities in Iran, mainly due to their restricted distributions, but some populations are also subjected to collection for medicine. Because of their beauty, rarity and dramatic stations, Dionysias are among the few plants referred to in Iranian tourist information. (Reference: Magnus Lidén 2007--The genus Dionysia (Primulaceae), a synopsis and five new species)
All species shown on this site were found in Iran, except Dionysia mira which
was found, and only grows, in Oman.