Dicranum undetermined

KEY TO IDENTIFICATION OF DICRANUM SPECIES WITH THE FLAGELLIFORM BRANCHLETS IN RUSSIA

1. Flagelliform branchlets few, arising terminally on stems; plants medium-sized to large; capsules inclined and curved; growing in bogs, rare on rocks. .......................................................... D. leioneuron View in CoL

– Flagelliform branchlets numerous, arising from axils of upper leaves; plants small to medium-sized; capsules erect, straight, cylindrical; growing on rotten wood, tree trunks and rocks ........................... 2

2. Leaves keeled, with recurved margins; epiphyte .... ............................................................. D. ignatovii View in CoL

– Leaves tubular, with plane margins; growing on rot- ten wood and rocks, occasionally on tree trunks. 3

3. Flagelliform branchlets not fragile, with deciduous leaflets of flagella (naked parts of branches are visible); dry stem leaves strongly crisped, 0.2–0.4 mm wide .................................................... D. montanum View in CoL

– Flagelliform branchlets fragile, with leaflets breaking off with pieces of branchlets; dry stem leaves slightly falcate-secund or curled to crisped, 0.4–0.9 mm wide ............................................................... 4

4. Stem leaves straight, patent or slightly falcate-secund when dry (very rarely curled); upper leaf cells short rectangular to quadrate; widespread. D. flagellare View in CoL

– Stem leaves curled to crisped when dry; upper leaf cells quadrate to transversely rectangular; South Siberia and Russian Far East ................................... 5

5 Costa with adaxial epidermis (occasionally fragmentary); leaflets of flagelliform branchlets with obtuse, incurved apices ........................................ D. mayrii View in CoL

– Costa without adaxial epidermis; leaflets of flagelliform branchlets with acute, recurved apices ........... ............................................................. D. afoninae View in CoL