11. Thuidium tamariscinum (Hedw.) Bruch & Schimp. in B. S. G. 密枝羽藓 mi-zhi yu xian
Bryol Eur. 5: 163, 482. 1852. Hypnum tamariscinum Hedw., Sp. Musc. Frond. 261. 1801. Type. France.
Thuidium tamariscifolium Lindb., Not. Sällsk. Fauna Fl. Fenn. Förh. 13: 415. 1874, hom. illeg.
Plants large, up to 15 cm long, yellowish green or brownish green, in densely interwoven mats. Stems procumbent, regularly bi- to tripinnately branched; branches about 1 cm long; central strand present; paraphyllia numerous, foliose or filamentous. Stem leaves appressed when dry, erecto-patent when moist, widely triangular to triangularly ovate, gradually tapering into a short acumen, slightly plicate, about 1.0–1.5 mm × 0.5–1.0 mm; margins serrulate; costa stout, vanishing at upper portion of leaf, often papillose on the back; leaf cells rhomboidal to oblong, median leaf cells about 6–20 µm long, unipapillose; branch leaves ovate to widely ovate, concave shortly acute, about 0.50 mm × 0.75 mm long; costa vanishing below leaf apex. Dioicous. Perichaetial leaves larger, sheathing at base, suddenly narrowed to a long reflexous apex, slightly ciliate at shoulder, serrate above, costa excurrent. Setae slender, reddish brown, up to 2 cm long, smooth; capsules cylindrical, slightly asymmetrical, about 3 mm long, horizontal, dark reddish brown; opercula conical; exostome teeth reddish brown, grossly papillose above; endostome segments as long as the teeth, finely papillose above; lightly yellowish; basal membrane about 1/2 the height of segments; cilia 2–3, finely papillose. Spores ca. 20 µm in diameter.