The Russian Far East is a phytogeographically quite peculiar region where a number of tropical and subtropical bryophytes penetrate to the north to the greater extend than in the other parts of the world. Some examples were discussed earlier by different authors, e. g. Herpetineuron toccoae, Brachymenium nepalense, Thuidium cymbifolium, Taxiphyllum taxirameum (Bardunov & Cherdantseva, 1982), Campylopus umbellatus (Ignatova & Samkova, 2006), Actinothuidium hookeri (Ignatov et al., 2000), etc.During the field trip in this area in 2007, we found one more species beyond its earlier known southern range; at the same time, this species is also a new addition to the Russian moss flora.
Fissidens hyalinusWilson & Hooker f., J. Bot. (Hooker) 3: 89. 1841.Figs. 1-2. Plants 1.5-3 mm, growing by solitary shoots or in small groups. Stem unbranched, loosely complanately foliate; central strand absent. Leaves in 4-5 pairs, broadly elongate, acute, to 0.5-1.6 х 0.2-0.3 mm; dorsal lamina narrowed proximally, ending at insertion, not decurrent; vaginant laminae about 1/3 of leaf length, equal; margins entire, bordered, border 1-3 cells wide, 1-2 cells thick, reaching apex or ending 1-3 cells below apex, indistinct or absent in vaginant laminae; costa absent; laminal cells unistratose, smooth, 20-50 х 15-35 μm, hexagonal, thinwalled. Only female plants with immature ga-