1. Rhytidiadelphus japonicus(Reim.) T. Kop. 仰尖拟垂枝藓 yang jian ni chui zhi xian
Hikobia 6: 19. 1971. Rhytidiadelphussquarrosus (Hedw.) Warnst. subsp. japonicus Reim. in Reim & Sak., Bot. Jahrb. Syst. 64: 559. 1931. Type: Japan.
Rhytidiadelphuscalvescens (Lindb.) Broth. var. densifolius Card., Bull. Soc. Bot. Genève, ser. 2, 5: 324. 1913.
Plants usually robust, ca. 15 cm long, reddish brown, with innovations. Stems prostrate, remotely foliate, irregularly branched; branches short, gradually becoming slender toward the apex, often producing branchlets. Stem leaves squarrose, broadly rounded-ovate to round, abruptly constricted into a short and curved apex, ca. 2.5 mm × 2.0 mm, hardly decurrent at base; margins toothed above; branch leaves erect-spreading in upper branches, broadly ovate, smaller than stem leaves; marginal teeth sharper than those of stem leaves; median leaf cells 45–55 µm × 5.5–6.0 mm, thin-walled, somewhat collenchymatous; basal cells rectangular, thick-walled; alar cells clearly differentiated, loosely arranged, rectangular or hexagonal, 28–32 µm × 15–20 mm, thick-walled, pitted. Inner perichaetial leaves lanceolate, ca. 2.5 mm long, long-acuminate, toothed above. Perigonia on stems; inner perigonial leaves long-acuminate. Setae 30–40 mm long, reddish brown, twisted; capsules horizontal, oblong-ovoid, 2.5 mm × 1.5 mm; opercula conic, slenderly rostrate, ca. 0.8 mm long; exostome teeth ca. 0.6 mm long, yellowish brown above, hyaline below; endostome segments as high as the teeth; cilia 3, as long as the segments.