1. Paludella squarrosa (Hedw.) Brid. 沼寒藓 zhao han xian
Muscol. Recent. Suppl. 3: 72. 1817. Pohlia squarrosa (Hedw.) Spreng., Syst. Veg. 4(1): 188. 1827. Orthopyxis squarrosa (Hedw.) P. de Beauv., Prodr. Aethéogam. 79. 1805. Hypnum squarrosum (Hedw.) Web. & Mohr, Index Mus. Pl. Crypt. 3. 1803, hom. illeg. Bryum squarrosum Hedw., Sp. Musc. Frond. 186. 1801. Type: Europe.
Plants robust, bright green or yellowish green above, brownish below, compact or in dense tufts, with brownish rhizoids at base. Stems erect, 8–15 cm high, simple or branched at top; central strand somewhat differentiated. Leaves more or less in 5 ranks, oblong-lanceolate or ovate-lanceolate, 1.0–2.0 mm × 0.5–1.0 mm, gradually acuminate, squarrose above, with twisted tips, decurrent at base; margins revolute below mid-leaf, plane and irregularly denticulate above; costae slender, ending below the apex; upper leaf cells rounded-hexagonal, mammillose on both sides; median cells elliptic; basal cells rectangular, thin-walled, hyaline; alar cells shorter. Dioicous. Perigonial leaves broadly ovate, squarrose at apex; perichaetial leaves longer than the stem leaves, erect or squarrose at tips, revolute at margins. Setae 3–6 cm long, reddish; capsules 4–5 mm long, elongate-ovoid, slightly curved; neck short, yellowish brown when young, reddish brown when mature; opercula conic at base, apiculate at apex; annuli in 2 rows; peristome double; exostome teeth 16, lanceolate, pale yellowish, papillose; endostome segments linear, nearly as long as or slightly shorter than the teeth, perforate; basal membrane ca. 1/5 the height of the teeth; cilia very short or absent. Spores small, 13–20 µm in diameter, minutely papillose.