Plants small, dull yellowish green, sometimes with a reddish cast. Stems 1-2 cm. Leaves 4-8 × 0.4-0.8 mm, narrowly ligulate to oblong-lanceolate above, concave, strongly undulate, with prominent teeth in oblique rows on abaxial surface corresponding to the undulations, margins with mostly double teeth; costa subpercurrent, toothed on the back above; lamellae 6-9(-12), with wavy margins, 5-10(-15) cells high, widely spreading and covering much of the leaf surface; median cells of lamina 8-17(-19) µm wide, ± isodiametric with firm walls, bulging-mammillose on adaxial surface, usually with prominent minute, rounded or striate papillae, especially on the abaxial surface. Sexual condition dioicous; male plants about same size or smaller than females, the perigonial bracts broad, forming conspicuous antheridial buds, often with more than one bud in sequence per plant. Seta 1-3 cm, erect, typically 1 per perichaetium. Capsule 3-7 × 0.3-0.6 mm, narrowly cylindric, usually ± straight to somewhat curved, suberect or inclined. Spores 11-16 µm.
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