Krypt.-Fl. Brandenburg, Laubm. 2: 878. 1906. Amblystegium riparium (Hedw.) Schimp. in B.S.G., Bryol. Eur. 6: 58. 1853. Hypnum riparium Hedw., Sp. Musc. Frond. 241. 1801. Type: England.
Leptodictyum riparium subsp. brevipes (Cardot & Thér.) Grout, Moss Fl. N. Amer. 3: 66. 1931. Amblystegium brevipes Cardot & Thér. in Holzinger, Minnesota Bot. Stud. 3: 124. 1903.
Plants rather robust, yellowish or greenish, in loosely caespitose mats. Stems prostrate, to 5–10 cm long, irregularly branched. Stem and branch leaves similar, erect or spreading, elongate-lanceolate, 2.5–4.0 mm × 0.5–0.8 mm, plane or somewhat curved, gradually acuminate at apex; margins entire; costae slender, single, reaching 1/2–3/4 the leaf length; median leaf cells shortly rhomboidal to elongate-rhomboidal, 60–80 mm × 9–12 mm; alar cells rectangular, indistinctly differentiated. Dioicous. Inner perichaetial leaves with a thick costa, reaching close to leaf apex. Setae 10–30 mm long, reddish; capsules 1.0–2.5 mm long, orange, arching curved. Spores 9–13 mm in diameter, minutely papillose.