2. Actinothuidium (Besch.) Broth. 锦丝藓属 jin-si xian shu
Nat. Pflanzenfam. I(3): 1019. 1908. Thuidium sect. Actinothuidium Besch., Ann. Sci. Nat., Bot., ser. 7, 15: 82. 1891.
Plants very stout, robust, rarely slender, yellowish green to brownish green, somewhat shining, in tufted or large cushions or mats. Primary stems erect, simple, sometimes forked; secondary stems densely pinnately branched; paraphyllia multibranched, dense on stems and branches; rhizoids reddish brown at lower portion of stems, rarely at the apex of branches. Stem leaves and branch leaves more or less polymorphic; stem leaves appressed when dry, widely cordate, gradually narrowed to a lanceolate acumen, deeply plicate, secund above; margins slightly revolute above, remotely dentate; costa thick, vanishing near leaf apex; leaf cells oblong-rhomboidal or oblong-hexagonal, slightly papillose at upper corners; thin-walled, hyaline; branch leaves ovate, with short lanceolate apex. Dioicous. Setae slender, up to 5 cm long; capsules cylindrical, inclined or horizontal, slightly curved; annuli differentiated, caducous when mature; opercula conic; peristome double; exostome teeth narrowly lanceolate, trabeculate below; endostome segments nearly as long as the teeth, lanceolate, pale yellowish, perforated, smooth; basal membrane high; cilia 3, shorter than the segments, smooth, nodulose. Calyptrae not seen. Spores not seen.