3. Claopodium gracillimum (Card. & Thér) Nog. 细麻羽藓 xi ma-yu xian
J. Hattori Bot. Lab. 27: 33. 1964. Diaphanodon gracillimus Card. & Thér., Bull. Acad. Int. Géogr. Bot. 18: 2. 1908. Type. Japan: Kagoshima, Amami-oshima Is., Ferrie s.n.
Plants very slender, green to yellowish green, in loose interwoven mats. Stems creeping, spreading, ca. 1.5 cm long, irregularly pinnately branched; branches remote, ca. 3 mm long; central strand differentiated; paraphyllia sparse, foliose. Stem leaves and branch leaves similar; stem leaves appressed when dry, erect-spreading when moist, ovate to ovate-triangular, acuminate above, ca. 0.3–0.4 mm long; leaf margins finely serrate; costa weak, reaching 2/3 leaf length; leaf cells hexagonal to rhomboidal, 12–20 µm × 4–8 µm, thin-walled, with a central papilla; branch leaves ovate to oblong-ovate, concave. Sporophytes unknown.