Echinophyllum sachalinense (Lindb.) T. J. O’Brien 刺叶藓 ci ye xian
Bryologist 103: 513. 2000. Bryochenea sachalinensis (Lindb.) C. Gao & G.-C. Zhang, Bull. Bot. Res., Harbin 2: 118. 1982. Helodium sachalinense (Lindb.) Broth., Nat. Pflanzenfam. I(3): 1018. 1908. Thuidium sachalinense Lindb., Contr. Fl. Crypt. As. 244. 1872. Type: Russia. Sachalin, Glehn s.n. (holotype H-Sol., not seen).
Tetracladium osadae Sakurai, Bot. Mag. (Tokyo) 5: 553. 1941.
Plants medium-sized, ca. 3 cm long, narrowed at base, yellowish green or green above, in interwoven patches. Stems creeping, irregularly pinnately branched; branches ca. 5 mm long; central strand present; paraphyllia densely growing on stems and branches, foliose or filamentous, irregularly branched. Stem leaves appressed on the stems when dry, erect-spreading when moist; branch leaves cordate, ovate or triangular at base, suddenly narrowed to a lanceolate apex, ca. 1.5–2.0 mm long; costa vanishing in the middle or above the middle portion of leaf, papillose on back; margins serrate, ciliate at base; leaf cells rhomboidal or rounded quadrate, ca. 15 µm × 8 µm, thick-walled, centrally unipapillose; branch leaves widely ovate, concave; costa reaching upper portion of leaf; cells of branch leaves rhomboidal or oval, ca. 15 µm × 8 µm. Dioicous. Perichaetial leaves serrate, setulosely or shortly ciliate at margins. Setae yellowish brown or reddish brown; capsules cylindrical, erect to horizontal, up to 4 mm long; peristome features similar to those of H. paludosum. Spores nearly rounded, ca. 15 µm in diameter, finely papillose.
This description is adopted from Helodium sachalinense (Lindb.) Broth. (P.-C. Wu et al. 2002).