Plants: small to large, in dense or loose tufts, light to deep green, sometimes yellowish, brownish, or rarely brownish red with age. Stems: creeping, ascending, or arching, not attenuate, loosely to densely terete- or rarely complanate-foliate, julaceous or not, irregularly to sometimes fairly regularly pinnate, branches somewhat more densely foliate than stem, terete- to complanate-foliate; central strand present; pseudoparaphyllia acute; axillary hairs of 2–3(–5) cells. Stem: leaves erect to patent and reflexed, loosely arranged to closely imbricate, broadly ovate, ovate-lanceolate, or deltoid, slightly to strongly concave, indistinctly plicate to not plicate; base broadly or narrowly short- or long-decurrent; margins coarsely serrate to subentire; apex gradually or abruptly tapered, acuminate, acute, or apiculate; costa reaching mid leaf to percurrent, strong, weak, or broad proximally and narrowed distally, terminal abaxial spine small or absent; alar cells subquadrate to short-rectangular, enlarged or not, walls thin or moderately thick; laminal cells slightly elongate (3–4:1) to linear (10–20:1), smooth (occasionally prorate abaxially in S. starkei), walls thin to moderately thick; basal juxtacostal cells undifferentiated, or broader and region pellucid, or slightly broader, walls moderately thick, and region opaque across base. Branch: leaves smaller, narrower; costal terminal spine more often present; laminal cells not prorate. Sexual: condition autoicous (dioicous in S. hylotapetum and S. latifolium); perichaetial leaves reflexed. Seta: red-brown or sometimes cherry red, rough or sometimes weakly so to almost smooth. Capsule: inclined, horizontal, or pendent, dark red-brown, elongate to short-ovate, straight or curved; annulus separating by fragments; operculum conic to long-conic, occasionally short-rostrate; peristome xerocastique, perfect. Calyptra: naked. Spores: 9–20 µm. Nearly worldwide, boreal and temperate zones, alpine to middle elevations in the tropics.

Species ca. 30 (11 in the flora). Sciuro-hypnum was segregated from Brachythecium by M. S. Ignatov and S. Huttunen (2002). Previously, species of Sciuro-hypnum were placed in Brachythecium in two sections: sect. Reflexa Brotherus and sect. Plumosa De Notaris (V. F. Brotherus 1924–1925). Sciuro-hypnum differs from Brachythecium in the mostly small plant size, the almost always autoicous sexual condition (except S. hylotapetum and S. latifolium), and rough setae. Among species of Brachythecium, the combination of autoicous sexual condition and a rough seta is uncommon in North America and is known only in B. bolanderi, B. campestre, and B. rutabulum. The stem leaves are occasionally twisted or falcate-secund. Immature capsules are sometimes strongly patent to circinate with the operculum turned upward.