The genus Dasystephana Adans. (Gentianaceae Juss.) in the flora of South Siberia

Abstract

A check-list of the genus DasystephanaAdans. (Gentianaceae)in South Siberia is given.A new section Septemfida is described and new combinations D. fetissowii and D. septemfida are published. In South Siberia, 14 species of Dasystephana are recorded, three of which belong to a high-mountain complex, five – to meadow-forest complex (including 2 lowland and 3 mountain species), four – to mountain-steppe complex and two – to mountain forest-steppe one. With regards to the geographical distribution, two species (D. sangilenica and D. vodopjanovae) are endemic, other two (D. cruciata, D. pneumonanthe) are predominantly European and reaching South Siberia at eastern limit of their distribution, three species (D. glauca, D scabra, D. triflora) are mainly East Asian and having a western limit of their area in South Siberia. Central Asian species D. dahurica, D. kaufmanniana, D. fetissowii have been found in South Siberia at the northern limit of their distribution. Other species are predominantly South Siberian. Of them, high-mountain D. algida also spreads to Central Asia and East Siberia, D. decumbens is also known from North Mongolia and (disjunctly) in the south of the Ural region. The forest-steppe D. macrophylla also occurs in northern parts of Mongolia and DzungarianAlatau being substituted by D. fetissowii southwards. Finally, D. fischeriis a South Siberian subendemic species (mostly confined to Altai). All Siberian species of Dasystephana have been found in South Siberia. Among them, D. pneumonantheis also known from the more northern regions of South-Siberian platform while D. algida spreads to the north-east of Siberia; D. decumbensand D. macrophylla reach southern regions of Yakutia. Distribution of species within the territory of Siberia is uneven: majority of them occur in the mountains of Altai and Transbaikalia (8 species in each region).