Ignatova, E.A., M.S. Ignatov, A.V. Fedorova
& J. Kučera. 2019. New Asian localities of Hymenostylium
xerophilum and H. gracillimum
Arctoa (2019) 28: 149–158
doi: 10.15298/arctoa.28.12
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.