Brachymenium exile (Dozy & Molk.) Bosch & Lac., Bryol. Jav. 1: 139. 1860.
Bryum exile Dozy & Molk., Ann. Sci. Nat. Bot. sér. 3, 2: 300. 1844. Protologue: Java, Sumatra.
Plants minute, yellow-green, gregarious or in tufts. Stems slender, 2–7 mm long, epidermal cells rectangular, sparsely tomentose at base; rhizoids reddish brown, lightly papillose. Leaves 0.5–0.8 mm long, erect-appressed to imbricate, spreading when wet, concave, ovate; apices short acuminate; margins weakly bordered by short-rectangular cells, entire, erect above, slightly reflexed below; costa stoutly short-excurrent, ventral superficial cells at base quadrate to rectangular; cells firm-walled throughout, upper cells hexagonal to rhomboidal-hexagonal, 30–50 x 10 μm, basal cells quadrate to short-rectangular, 10–20 x 10 μm. Bulbous axillary gemmae sometimes present. Dioicous. Setae 15–30 mm long, red. Capsules 1.5–2.0 mm long, claviform to obovate-oblong, constricted at neck, erect; opercula 0.3–0.5 mm long, conic; annuli compound, revoluble; exostome teeth whitish red, thickly papillose, endostome yellowish, papillose, basal membrane to ¾–_ the exostome teeth length, segments rudimentary, cilia rudimentary to absent. Spores 10–14 μm, lightly roughened. Calyptrae 1 mm long, cucullate, hyaline-yellow below, reddish above.