Wormwoods of Buryatia: diversity analysis, ecological-geographical features, and chemotaxonomy of section Abrotanum

The wormwoods of Buryatia includes 48 species and subspecies, which belong to three subgenus and seven sections (subgenus Artemisia, sections - Artemisia, Abrotanum, Absinthium, subgenus Dracunculus, sections - Dracunculus, Campestris, Psammophiiae, subgenus Seriphidium, section -Haiophiium. Most of the wormwoods of the region are xerophytes and mesoxerophytes, belonging to the steppe and forest-steppe ecological-coenotic groups (34 species, 70.8%), mainly from the sections of Artemisia, Abrotanum, and Campestris. Ecological-geographically, Central Asian, South Siberian, and North Asian species dominate, accounting for 45.8% of the total species composition with significant share of species with wide Eurasian distribution area (8 species, 16.6%). Endemism is peculiar to the species of psammophyte-steppe (Artemisia ledebouriana, A. xylorhiza) and mountain-steppe (Artemisia subviscosa) genesis (3 species, 6.25%). In the systematic relation, interpretations of a taxonomical variety on separate sections are ambiguous, among them there is Campestris, Absinthium, Abrotanum. In the section Abrotanum the identification of species close to Artemisia gmeiinii is problematic. As a result of a detailed study of the composition of the essential oil, the additional chemotaxonomic criteria for the taxonomic status of Artemisia messerschmidtiana and A. santoiinifoiia were suggested. So, the presence of davanone components in the oil of Artemisia santoiinifoiia can be the taxonomic sign of this species. Specific components in high concentrations were also found in the composition of Artemisia messerschmidtiana, namely trans-Sabinene hydrate (2.4%), gamma-Terpinene (2.0%), and Germacrene D (1.6%).