4. Entodon challengeri (Paris) Cardot 柱蒴娟藓 zhu shuo juan xian
Beih. Bot. Centralbl. 17: 32. 1904. Cylindrothecium challengeri Paris, Index Bryol. 296. 1894. Type: Japan.
Entodon compressus Müll. Hal. ex Cardot, Bull. Herb. Boissier 7: 346, hom. illeg. 1899.
Entodon microthecius Broth., Symb. Sin. 4: 112. 1929. Type: China. Yunnan, Yungbei, Handel-Mazzetti 6309.
Entodon nanocarpus Müll. Hal., Nuovo Giorn. Bot. Ital., n.s., 4: 265. 1897. Type: China. Shaanxi, Nov. 1895, Giraldi s.n.
4a. Entodon challengeri var. challengeri 柱蒴娟藓原变种 zhu shuo juan xian yuan bian zhong
Plants medium-sized, dark green or olive green, sometimes yellowish green or pale green, glossy. Stems prostrate, subpinnately branched, complanate, with branches 8–10 mm long. Stem leaves oblong-elliptical, 1.5–1.8 mm × ca. 0.8 mm, strongly concave, broadly obtuse at apex; margins entire; costae double, very short, sometimes absent; median leaf cells linear, 60–65 µm × 5.0–5.5 µm; apical cells shorter; alar cells numerous, hyaline, extending close to costa at leaf base. Autoicous. Perichaetial leaves long sheathing at base, long acuminate at apex. Setae 7–15 mm long, reddish brown; capsules oblong-ovoid to ellipsoidal, ca. 2.5 mm × 0.6 mm; opercula shortly conic-rostrate; annuli well developed, in 2–3 rows of inflated cells; exostome teeth narrowly lanceolate, 400–500 µm long, ca. 50 µm wide at base, densely papillose throughout; endostome segments linear, shorter than the teeth, densely papillose throughout. Spores spherical, 18–29 µm in diameter, minutely papillose.