5. Plagiothecium formosicum Broth. & Yasuda 台湾棉藓 tai wan mian xian
Rev. Bryol. 53: 3. 1926. Type: China. Taiwan, Mt. Daibu, Matsuda s.n.
5a. Plagiothecium formosicum var. formosicum 台湾棉藓原变种 tai wan mian xian yuan bian zhong
Plants small to medium-sized, soft, grayish green or yellowish green, somewhat glossy, in dense mats. Stems prostrate, irregularly branched, leafy branches 5–10 mm × 2–3 mm, complanate; central strand weakly differentiated. All leaves soft, usually plicate, ovate-lanceolate, 1.3–1.6 mm × 0.50–0.55 mm, distinctly asymmetric, often arch-curved, gradually acute at apex; margins plane or narrowly reflexed, entire or serrulate near the apex; costae forked, unequal in length; median leaf cells linear-rhomboidal, 80–130 µm × 5–7 µm; apical cells shorter; basal cells rectangular, porose; alar regions narrowly decurrent, consisting of 4 rows of inflated, mostly rectangular cells. Brood bodies and rhizoids often present at leaf apex. Dioicous. Perichaetial leaves shortly ovate-lanceolate, often plicate, sheathing at base. Setae 15–22 mm long; capsules inclined to horizontal, shortly cylindrical, 1.5–2.0 mm long; opercula shortly conic-rostrate, with a short beak; annuli well developed, consisting of 2 rows of deciduous cells; stomata few; peristome double; cilia 2, nodulose. Spores 10–20 µm in diameter, nearly smooth.