Dionysius

Dionysia pillow-shaped ( Dionysia tapetodes ), general view

Representatives of the genus are shrubs that form pillows or sods. In their form, they resemble rounded cushions formed by shortened, abundantly branching shoots that are closely adjacent to each other. The growth of shoots due to extremely adverse conditions is limited. Plants are characterized by continuous, albeit slow, growth; therefore, annual rings do not form in wood .

The leaves are imbued, rarely form rosettes . The leaves are small, densely seated, dying from the bottom, whole-edge or serrated, flat or bent along the edge, in many species they have a whitish or yellowish powdery coating, less often with simple pubescence.

The flowers are bisexual, sometimes dichogamous, actinomorphic, five-membered, yellow, occasionally purple, mostly single, at the tops of shoots, less often two or five in umbrellas, peduncles , with pedicels . Two to three renewal buds are under the flowers. Bracts , including one to three, lanceolate or linear, whole-edge, rarely dentate, including three to five, form a rosette under the base of the umbrella. Perianth is leafy. Calyx deep, almost to the base, or at least ¾ separate, bell-shaped or goblet, remaining with the fetus. The corolla is tubular-nail-shaped, with a long tube, four to six, less often two to three times the cup, cylindrical, often slightly curved or in the middle or under the pharynx suddenly expanded. Pharynx without scales, naked. Lobes of the limb are ovoid or reverse heart-shaped, whole-edge or notched. Stamens attached to the cup and located opposite to its lobes, almost sessile. The stamen filaments are usually loose and short. The column is threadlike. Stigma spherical-capitate. Gynoecium consists of five carpels . Ovary superior, single-membered, round or flat-round. Dionysius is characterized by dimorphic heterostyly and the associated cross-pollination.

Fruit - a single-nodule capsule , round or ovoid, cracking to the base with five wings, glabrous. Seeds , including one to four, rarely up to 15, are very small, brown or black, ovoid or almost round, keeled, finely wrinkled, or with a surface covered with small papillae, have a small germ and a plentiful endosperm . Like all primroses, by the nature of the scattering of seeds, Dionysius belongs to anemochoric ballistas, but some of its species themselves scatter seeds. A few weeks after the ripening of the seeds, the capsules suddenly open and the seeds themselves fly out of them.

The range of most types of Dionysius is small and confined to one ridge, mountain or its slope. The extinction of species from their habitats is associated with the construction of roads, as well as with the collection of plants by collectors for planting on alpine hills. The number of species is also decreasing due to livestock grazing.

In Central Asia, on the southern slope of the Gissar Range, in the valley of the Varzob River, at an altitude of 950-1800 m above sea level, on the granite cliffs, the narrow -areal relic endemic of Dionysia wrapper grows ( Dionysia involucrata ). In this gorge, there are 25 places where from 5 to 120 pillows of Dionysius are found. Some plants were destroyed during the construction of mountain roads, which led to the actual destruction of the species.

Dionysia Kosinsky ( Dionysia kossinskyi ) was described by single finds in the mountains of Central Kopetdag at an altitude of 1600-2800 m above sea level. According to recent studies, it was found that Kosinsky dionysia from its former habitat in the Kopetdag mountains has disappeared. While it can still be found in Iran.

Dionysia Hissar ( Dionysia hissarica ), wrapping and Kosinsky were included in the Red Book of the USSR. The amazing Dionysia ( Dionysia mira ) is bred in the Kew Botanical Gardens and is included in the IUCN Red List.

The genus has 54 species ^[2] :