Weissia, Hedwig, 1801

Inoue, Yuya & Tsubota, Hiromi, 2017, A taxonomic revision of cleistocarpous species of Weissia (Pottiaceae, Bryophyta) in Japan, Phytotaxa 306 (1), pp. 1-20 : 9

Key to the cleistocarpous species of Weissia in Japan

1. Perichaetial leaves little differentiated from vegetative leaves; capsules with functionally dehiscent operculum (spore release with opening of capsule mouth) .................................................................................................................................Stegocarpous species

- Perichaetial leaves well differentiated and much larger than vegetative leaves; capsules without functionally dehiscent operculum (spore release with irregular dehiscence of capsule)..........................................................................................................................2

2. Annulus absent .................................................................................................................................................................... W. kiiensis

- Annulus present..................................................................................................................................................................................3

3. Seta 0.5–1.2 mm long; capsules exserted from perichaetial leaves; urn ellipsoidal ........................................................... W. exserta

- Seta less than 0.4 mm long; capsules deeply immersed among perichaetial leaves; urn ovoid to subovoid.....................................4

4. Urn (550–)625–750(–840) × (450–)505–600(–720) μm; costa excurrent in a point reaching (80–)90–130(–160) μm... W. japonica

- Urn (400–)500–660(–760) × (360–)415–515(–620) μm; costa excurrent in a point reaching (80–)100–250(–280) μm.................... ................................................................................................................................................................................... W. parajaponica