13. Dicranella rufescens (With.) Schimp. 红色小曲尾藓 hong-se xiao qu-wei xian.
Coroll. Bryol. Eur. 13. 1856. Bryum rufescens With., Syst. Arr. Brit. Pl. (ed. 4) 3: 801. 1801. Type. Scotland.
Plants small and slender, up to 7 mm high, dull, brownish or reddish brown, gregarious or in loose tufts. Stems erect, simple or branched. Leaves erect-spreading to subsecund, linear-lanceolate, lower ones shorter and rather distant, 0.8–1.0 mm long, upper ones longer and more crowded, up to 1.5 mm long, gradually narrowed to a more or less keeled acumen, acute at the apex; margins plane, crenulate above the shoulder, becoming serrulate near the apex; costa stout, subpercurrent to short-excurrent, occupying ca. 1/5 the leaf base width; upper cells long-rectangular, 40–50 µm × 8–14 µm, a row of marginal cells slightly enlarged. Dioicous. Perichaetial leaves larger, costa long-excurrent from a subulate acumen. Setae straight, 4–5 mm long, reddish brown; capsules short-cylindric, 0.3–0.4 mm × 0.2 mm, erect, symmetric or nearly so, smooth when dry; opercula stoutly rostrate, nearly as long as the urns or slightly shorter; annuli absent; peristome teeth lanceolate, ca. 350 µm long, slightly spreading when dry, divided about 1/3–1/2 down to the base. Spores 14–18 µm in diameter, nearly smooth.