Plants: small, in loose or moderately dense tufts, green to yellowish or brownish. Stems: to 4(–5) cm, creeping or ascending and erect, terete- to subcomplanate-foliate, not julaceous, regularly or irregularly pinnate, branches to 4(–6) mm, terete- or subcomplanate-foliate. Stem: leaves erect to erect-spreading, densely to loosely arranged, falcate to circinate, ovate-lanceolate to lanceolate, not plicate or with 2 submarginal plicae, rarely with additional indistinct plicae, 1–1.8 × (0.1–)0.2–0.5(–0.6) mm; margins plane or recurved at base, serrate, serrulate, or subentire; apex gradually long-acuminate, acumen weakly spreading; costa to 40–70% leaf length, often thick distally, terminal spine present; alar cells subquadrate to short-rectangular, 8–12 × 10–15 µm, region small, of 4–8 × 4–6 cells, distinctly delimited; laminal cells linear, 45–140 × 4–7 µm; basal cells short-rectangular, 8–10 µm wide, region in 1 or 2 indistinctly delimited rows. Seta: red-brown, 0.8–1.5 cm, smooth, rough, or rough proximally and smooth near capsule. Capsule: horizontal, brown, dark red-brown with age, elongate, to 1.5 mm; endostome basal membrane 1/3–1/2 endostome length, cilia as long as segments. Spores: 10–14(–15) µm. North America, Eurasia, n Africa, Atlantic Islands.
Varieties 2 (2 in the flora). Plants of Brachytheciastrum velutinum have less strongly plicate branch leaves than stem leaves.