Laubm. Deutschl. 3: 207. 1896. Rhynchostegium subgen. Rhynchostegiella Schimp. in B.S.G., Bryol. Eur. 5: 201. 1852.

 

Plants slender, soft, green or yellowish green, glossy, in loose mats. Stems prostrate, elongate, often with rhizoids, irregularly or subpinnately branched; branches short, densely foliate, usually complanate. Stem and branch leaves similar or dimorphic; stem leaves oblong-lanceolate or ovate-lanceolate, slightly concave; margins entire or serrulate above; costae single, variable in length, ending below mid-leaf to nearly percurrent; median leaf cells linear; alar cells differentiated, sometimes weakly so, quadrate to shortly rectangular; branch leaves lanceolate to narrowly lanceolate. Autoicous. Perichaetial leaves narrowly lanceolate, slenderly acuminate to piliform toward apex, sometimes reflexed. Setae elongate, reddish, twisted; capsules suberect to horizontal, ovoid to elongate-ovoid; opercula conic, long rostrate; peristome double; exostome teeth cross-striolate at base, smooth or papillose above, trabeculate on ventral surface; endostome segments linear-lanceolate, perforate; basal membrane high; cilia nodulose. Spores unknown.

 

1. Leaves plane; costae thin, faint, ending below mid-leaf or shorter, at ca. 1/3 the leaf length; median leaf cells 110–135 µm × 10–11 µm..................................................................................................... 3. R. leptoneura

1. Leaves concave, or more or less so; costae thick, ending well beyond mid-leaf or close to leaf apex; median leaf cells 63–96 µm × 6–8 µm................................................................................................................................ 2

2. Stem and branch leaves similar, ovate-lanceolate to narrowly ovate-lanceolate or elliptical-lanceolate; costae ending at mid-leaf or slightly above.................................................................................. 1. R. japonica

2. Stem and branch leaves dimorphic; stem leaves ovate-lanceolate; branch leaves narrowly lanceolate; costae ending in leaf acumen or nearly subpercurrent................................................................ 2. R. laeviseta