4.
Drepanocladus sendtneri (Schimp.) Warnst. 粗肋镰刀藓 cu le lian dao xian Beih. Bot. Centralbl. 13: 400. 1903.
Amblystegium sendtneri (Schimp.) De Not., Atti Reale Univ. Genova 1: 139. 1869.
Hypnum sendtneri Schimp., Verh. Naturhist. Vereines Preuss. Rheinl. Westphalens 3, 21: 117. 1864. Type: Europe.
Drepanocladus sendtneri fo.
trivalis (Sanio) Mönk., Laubm. Eur. 765. 1927.
Drepanocladus sendtneri var.
trivalis (Sanio) Warnst., Krypt.-Fl. Brandenburg, Laubm. 1015. 1906.
Hypnum aduncum fo.
trivalis Sanio, Bot. Centralbl. 4 (Gratisbeil. 2). 1880.
Drepanocladus sendtneri fo.
wilsonii (Lindb.) Mönk., Laubm. Eur. 765. 1927.
Drepanocladus sendtneri var.
wilsonii (Lindb.) Warnst., Krypt.-Fl. Brandenburg, Laubm. 1016. 1906.
Drepanocladus wilsonii (Lindb.) Loeske, Moosfl. Harz. 305. pl. 51, f. 11. 1903.
Hypnum intermedium var.
wilsonii Lindb., Öfvers. Förh. Kongl. Svenska Vetensk.-Akad. 23: 540. 1867.
Plants usually robust, aquatic or semi-aquatic, yellowish green or yellowish brown, in dense mats.
Stems prostrate, ascending or erect, to ca. 30 cm long, pinnately or irregularly branched; central strand not or weakly differentiated.
Stem leaves falcate-secund, ovate-lanceolate, 1.5–2.5 mm × 0.4–1.0 mm, concave, sometimes plicate, gradually narrowed toward a long acuminate apex; margins nearly entire; costae single, thick, ca. 80–100 mm wide at base, usually reaching near leaf apex; median leaf cells linear, 70–120 mm × 7–9 mm; basal cells brownish, thick-walled, porose; alar cells few, yellowish, rectangular, thick-walled, porose, sometimes forming auricles.
Dioicous.
Perichaetial leaves oblong-lanceolate, plicate.
Setae 30–40 mm long, purple; capsules curved, cylindrical.
Spores 12–17 mm in diameter, papillose.
