5. Racomitrium brevisetum Lindb. 短柄砂藓 duan-bing sha xian
Contr. Fl. Crypt. As. 244. 1872. Grimmia breviseta (Lindb.) Lindb. & Arn., Kongl. Svenska Vetenskapsakad. Handl. 23(10): 102. 1890. Type. Russia: Sakhalin, July 1860, Schmidt s.n.
Racomitrium fasciculare var. brachyphyllum Card., Bull. Herb. Boissier, ser. 2, 8: 334. 1908.
Plants stiff, small or sometimes medium-sized, up to 2(–3) cm long, green above, dark brownish below, in loose tufts. Stems creeping or sometimes ascending, sparsely and irregularly branched; central strand absent. Leaves loosely imbricate, slightly secund when dry, erect-spreading when moist, broadly ovate-lanceolate, somewhat concave and keeled above, plicate below, 2.4–2.7 mm long, bluntly acuminate, occasionally with denticulate apex; margins recurved on both sides; costa slender, extending up to 2/3–3/4 the leaf length; upper leaf cells short-rectangular, 7–12 µm × 6–7 µm, sinuosely thick-walled, coarsely papillose, often with forked papillae, unistratose at margins; median cells rectangular, 9–23 µm × 5–7 µm, sinuosely thick-walled, papillose; basal cells elongate-rectangular to linear, 18–40 µm × 4–5 µm, strongly sinuosely thick-walled, nearly smooth; alar cells not differentiated, with only a row of hyaline, thin-walled, rectangular cells on the basal margins, 12–18 µm × 5–8 µm. Perichaetial leaves larger than stem leaves. Setae short, 4–6 mm long, erect, brownish, twisted when dry; capsules erect, ovoid, ca. 1.5–1.6 mm long; opercula long rostrate; peristome teeth linear-lanceolate, reddish brown, divided to the base. Spores small, 9–12 µm in diameter, yellowish, minutely papillose.