Pylaisia, IN

Ignatova, E. A., Kuznetsova, O. I., Shafigullina, N. R., Fedosov, V. E. & Ignatov, M. S., 2020, The genus Pylaisia (Pylaisiaceae, Bryophyta) in Russia, Arctoa 29 (1), pp. 135-178 : 145-146

KEY TO SPECIES IDENTIFICATION OF PYLAISIA IN RUSSIA

1. Endostome free; segments keeled, solid at apex, entire or perforated along the keel ........................... 2

— Endostome adherent to exostome, at least at base; segments usually split or perforated along the keel, rarely entire, or totally adherent to exostome teeth and fragmentary ..................................................... 6

2. Branches julaceous; stem leaves broadly ovate, acute to shortly acuminate, shorter than 1.1 mm, strongly concave; median laminal cells 20–45 µm long ...... ...................................................... 4. P. curviramea

— Branches non-julaceous; stem leaves ovate-lanceolate, short to long acuminate, (0.6–)0.9–1.5(–1.7) long, slightly or moderately concave; median laminal cells 30–75(–90) µm long ............................... 3

3. Foliage non-complanate; stem and branch leaves straight to homomallous and turned outwards substrate ...................................................................... 4

— Foliage complanate; stem and branch leaves more or less falcate, turned towards substrate ............... 5

4. Stem leaves 1.1–1.5(–1.7)×0.5–0.6(–0.7) mm; laminal cells 35–70(–90)×5–6(–7) µm; spores (10–)11– 16(–18) µm; widespread .................. 1. P. polyantha

— Stem leaves 0.6–1.1× 0.3–0.4 mm; laminal cells 35– 75×4–5 µm; spores 9–12(–13) µm; eastern part of Russia.................................................. 2. P. coreana

5. Plants small to medium-sized; stem leaves 1.1–1.6 mm long; alar group triangular, to 10–15 cells long and 5–10 cells wide; spores 12–18 µm; endostome densely papillose ................................... 3. P. steerei

— Plants small; stem leaves 0.9–1.2 mm long; alar group elongate along leaf margin, 12–22 cells long and 5–6 cells wide; spores 10–12 µm; endostome moderately papillose .......................5. P. bezgodovii

6(1). Endostome totally adherent to exostome teeth, fragmentary; alar group triangular, 10–14 cells along leaf margin ................................... 11. P. stereodontoides

— Endostome partially adherent to exostome teeth, not fragmentary; alar group comparatively small, subquadrate or transversely rectangular, 7–15(–20) cells along leaf margin, or elongate, extensive, 20–35 cell along leaf margin ................................................... 7

7. Alar group subquadrate or transversely rectangular, 7–15(–20) cells along the leaf margin .................. 8

— Alar group elongate, 20–35 cell along the leaf margin ........................................................................ 10

8. Endostome segments free, broad, keeled, but at the level of basal membrane endostome is partly adherent to exostome, and split along the continuation of the keel; leaves falcate; spores 19–22 µm ............... ...................................................... 6. P. camurifolia

— Endostome adherent to exostome teeth to the base of segments or higher; leaves falcate or straight; spores 15–35 µm .............................................................. 9

9. Operculum obtuse or with stump-like truncate beak; endostome adherent to exostome at a level of basal membrane, segments bifid, with free broad branches; leaves homomallous or looking falcate on stems, but in microscope slides more or less straight ........ ........................................................... 10. P. obtusa

— Operculum shortly rostrate; endostome segments partially adherent to exostome teeth, their ends are entire or bifid with narrow branches; leaves falcate on stems and strongly curved in microscope slides .................................................... 9. P. subcircinata

10(7). Leaves rather abruptly narrowed to a short acumen; alar group 20–25 cells long and 6–10 cells wide; median laminal cells 25–40(–50)×6–9 µm; inner perichaetial leaves comparatively short, ca. 1.5 mm long; capsules oblong-ovoid; spores 16–30 µm ...... ....................................................... 7. P. condensata

— Leaves gradually, rarer more or less abruptly narrowed into a long acumen; alar group 25–35 cells long and 10–12 cells wide; median laminal cells 40– 55×4–5 µm; inner perichaetial leaves comparatively long, ca. 2.0 mm long; capsules ovoid to subglobose; spores 20–30 µm ................................. 8. P. brotheri