Ignatova E.A.1, Ignatov M.S.1,2, Fedorova A.V.2, Kučera J.3 2019. New Asian localities of Hymenostylium xerophilum and H. gracillimum // Arctoa. Vol. 28: 149–158 [in English].
1 – Lomonosov Moscow State University, Faculty of Biology, Plant Ecology and Geography Dept., Leninskie Gory Str. 1-12, Moscow 119234 Russia; e-mails: email@example.com, firstname.lastname@example.org
2 – Tsitsin Main Botanical Garden, Russian Academy of Sciences, Botanicheskaya Str., 4, Moscow 127276 Russia; e-mail: email@example.com
3 – University of South Bohemia, Faculty of Science, Department of Botany, Branišovská 1760, CZ–370 05 České Budějovice, Czech Republic, e-mail: firstname.lastname@example.org
KEYWORDS: Hymenostylium, Pleuroweisieae, Asia, Siberia, disjunct distribution, metalliferous rocks, molecular phylogeny, ITS, rps4, trnM–trnV
ABSTRACT. We report here the new, highly disjunct Asian occurrences for two Hymenostylium species, which have so far only been known from Europe. Hymenostylium xerophilum is newly reported from Oman and eastern Yakutia, while the other species, H. gracillimum was found among herbarium material collected at the shore of Lake Baikal in southern Siberia. While the new H. xerophilum records matched both the earlier described morphology of the plants and ecological preferences, the plants of H. gracillimum were morphologically and probably also ecologically rather distinct from the known European material. Molecular phylogenetic analysis of Pottiaceae trib. Pleuroweisieae based on nuclear ITS region and two chloroplast loci was performed to assess newly the phylogenetic affinities of the two species and to confirm the identity with the European plants. The lineage formed by accessions of these two species was confirmed as rather distinct from the rest of analyzed Hymenostylium taxa and pointed to the necessity of a large-scaled study of Hymenostylium and related genera. We discuss the ecological and phytogeographic characteristics of the new Asian occurrences.