Epipterygium

Hanusch, Maximilian, Ortiz, Edgardo M., Patiño, Jairo & Schaefer, Hanno, 2020, Biogeography and integrative taxonomy of Epipterygium (Mniaceae, Bryophyta), TAXON 69 (6), pp. 1150-1171 : 1164-1165

Key to the species of Epipterygium

Small or very small, delicate, cespitose or loosely tufted, pale green, reddish-green to yellowish or white, beamless or shiny plants. Stems simple, reddish to green, sometimes branched at basis, erect to decumbent or reclining. Rhizoids forming at stem base. Leaves dimorphous, sometimes less distinctly on fertile stems. Dorsal leaves shorter, more tapered, obliquely protruding from stem in one or two rows. Leaves distant at base, more crowded and larger at stem tips, loosely spreading, thin, elliptic, ovate or obovate to oblong-lanceolate, acute or abruptly short-acuminate, more or less decurrent. Leaf margins entire, with a distinct or less marked, often reddish border. Perichaetial leaf apex sometimes serrate. Costa slender, extending one-half to five-sixths of the leaf length. Cells pale, lax, delicate, thin-walled, rhomboidal to irregularly rhomboidal, narrower and longer at leaf margins forming a more or less distinct border.

This key covers all species examined in the present study. Five species of the genus are not covered by this key due to lack of material: E. brasiliense E.B.Bartram , E. koelzii H.Rob. , E. mandonii (Müll.Hal.) Paris , E. rigidum Lindb. , and E. vanuatuicum H.A.Mill.

1. Stems with one row of smaller ventral leaves; Old World.............................................................................2

1. Stems with two or no rows of smaller ventral leaves; New World.............................................................................7

2. Gametophyte up to 5 mm long.......................................3

2. Gametophyte more than 5 mm long...............................5

3. Plants complanate, green to red; broadly ovate lateral leaves, 1.5–2.1 mm in length, median cell length 90– 150 μm; oceanic climate; western Europe, Macaronesia ....................................................................... E. atlanticum

3. Plants not complanate, leaves ± spreading; Africa, Asia.....................................................................................4

4. Lateral leaves up to 1.5 mm long, perichaetial leaf tip serrate; Himalayas: Bhutan, Nepal, China...................... ................................................................ E. oreophilum

4. Lateral leaves up to 3.3 mm long, perichaetial leaf tip not serrate; Africa: Bioko, Uganda................. E. convalleum

5. Perichaetial leaves not serrate, leaves not distinctly bordered, median cell length up to 225 μm; Europe: Mediterranean, Madeira .................................................. E. tozeri

5. Perichaetial leaves serrate, leaves distinctly bordered, median cell length up to 130 μm, Asia: Japan, China...... 6

6. Costa ending just below apex, median cells 25–30 μm wide; Japan............................................. E. nagasakense

6. Costa ending well below apex, median cells 28–40 μm wide; China: Yunnan, subtropical highland climate ........ ................................................................. E. yunnanense

7. Plants strongly complanate and dimorphous-foliate or non-dimorphous foliate, leaves strongly or weakly bordered, red or pale green leaves; New Zealand, West Indies.............................................................................8

7. Plants weakly or sometimes strongly complanate and dimorphous foliate, green or pink; median cells 8–30 μm wide; temperate and tropical North, Central or South America......................................................................... 10

8. Gametophyte up to 15 mm long, pale green plants, leaves monomorphic; New Zealand..................... E. opararense

8. Gametophyte up to 30 mm long, reddish, rarely green plants, leaves dimorphic; West Indies............................9

9. Median cells regularly rhomboidal, lateral leaves broadly elliptical to oblong; West Indies, Cuba, Jamaica............. ........................................................................ E. wrightii

9. Median cells irregularly rhomboidal, lateral leaves orbicular to ovate; West Indies and northern South America .................................................................... E. orbifolium

10. Plants glossy, green; leaves scarcely bordered; cells 8–16 μm wide; Central America .............. E. mexicanum

10. Plants dull, bluish-green to pink; leaves often bordered; cells 16–30 μm wide....................................................11

11. Plants scarcely or not at all complanate or dimorphous-foliate, leaves lanceolate; temperate America .................. ..................................................................... E. biauritum

11. Plants weakly or often strongly complanate and dimorphous-foliate, leaves elliptical; tropical America.........12

12. Lower leaves orbicular to ovate, not distinctly bordered; tropical America, South America ................. E. puiggarii

12. Lower leaves elliptical, plants weakly or often strongly complanate and dimorphous-foliate; tropical America .... ............................................................ E. immarginatum