Ignatova, E.A., O.I. Kuznetsova, N.R. Shafigullina, V.E. Fedosov & M.S. Ignatov. 2020. The genus Pylaisia (Pylaisiaceae, Bryophyta) in Russia

Arctoa (2020) 29: 135178

doi: 10.15298/arctoa.29.11


The genus Pylaisia is revised for the Russian moss flora basing on morphological and molecular phylogenetic studies of nuclear ITS and IGS markers and plastid trnL-F. The main subdivision of the genus in the obtained phylogeny splits it into two clades. The first clade includes species with the endostome totally adherent to exostome; it is represented in Russia only by P. stereodontoides that is related to North American P. intricata and more southern East Asian P. cristata. The second clade includes a rather well supported clade composed of species with endostomes rather strongly adherent to exostome (P. brotheri, P. condensata, P. obtusa, P. subcircinata), that is nested in a polytomy of species with endostomes either free or only a little adherent to exostomes. The latter polytomy includes P. polyantha, P. curviramea, P. steerei, P. coreana, P. bezgodovii sp. nov., and P. camurifolia (= Asiatic P. falcata). Asian P. condensata differs from the North American P. selwynii, thus they may not be considered as synonymous, as it was usually assumed. A complicated diversity is found within P. polyantha s.l. in TCS network of ITS haplotypes: a group of European and North American haplotypes is the most isolated; mainly Siberian group of haplotypes is moderately delimited whereas the Far Eastern haplotypes form a reticulation with P. steerei and P. curviramea, and also a small-sized plants with free endostomes of P. polyantha-group. The latter form a moderately supported clade in IGS based trees and has morphological distinctions, allowing its resurrection as a separate East Asian species, P. coreana. One Genbank accession from Alaska referred to P. selwynii is deeply nested in P. obtusa, thus we presume that the latter species occurs in North America.