4. Rhynchostegium ovalifolium S. Okamura 卵叶长喙藓 luan ye chang hui xian
J. Coll. Sci. Imp. Univ. Tokyo 38(4): 94. 1926. Type: Japan. Honshu, Pref. Mie, Murata s.n.
Plants rather robust, pale green, in loose mats. Stems prostrate, to ca. 5 cm long, irregularly branched, densely foliate; branches blunt or attenuate at tips. Stem and branch leaves more or less similar, broadly ovate, 1.58–1.90 mm × 0.81–1.17 mm, acute or apiculate at apex, occasionally bent; margins serrulate, slightly recurved at base; costae reaching ca. 2/3 the leaf length; median leaf cells elongate-rhomboidal, 50–80 µm × 9–13 µm; alar cells few, lax, shortly rectangular to rectangular, somewhat thick-walled, extending close to costa at leaf base. Perichaetial leaves slenderly lanceolate. Setae elongate, ca. 20 mm long; capsules oblong-ovoid, inclined to horizontal; endostome segments as long as exostome teeth; cilia 2, as long as the segments. Spores not seen.