Ignatova,
E.A., H.H. Blom & O.I. Kuznetsova. Schistidium austrosibiricum sp. nov. and S.
scabripilum sp. nov. (Grimmiaceae, Bryophyta) – two
closely related species from Asian Russia
Arctoa
(2016) 25: 107–115
doi: 10.15298/arctoa.25.08
Two
new species of Schistidium are described from Asian Russia. Their
distinctness is supported by nrDNA ITS1-2 sequence data. S. austrosibiricum
was not previously differentiated from S. sinensiapocarpum, mainly due
to their similarly long and sharply serrate hair-points in stem and
perichaetial leaves and papillose dorsal side of costa. However, they differ in
leaf size and shape, hair-points flatness and leaf lamina areolation. S.
austrosibiricum is known from southernmost mountain areas of Asian Russia,
while S. sinensiapocarpum is a widespread circumholarctic montane
species. The second species, S. scabripilum is morphologically similar
to S. echinatum, and some specimens were previously referred to it. The
main differences between them concern hair-point length and structure,
including length of protruding spinulae and their angle with the hair-point
axis. However, they belong to different clades in the molecular phylogenetic
tree and possess different distribution patterns. S. scabripilum is a
northern Asian species, found in the Putorana Plateau, southern Taimyr, Yakutia
and Chukotka, while S. echinatum is known from the Alps, Caucasus and
Ural mountains, and in western North America. Description, illustrations,
distribution and ecological data are provided for the new species, and
comparison with similar species is given.