Ptychomitrium acutifolium

Cushions to c. 10 mm tall on calcareous or basaltic rocks. Stems covered in brown rhizoids, usually branched. Leaves linear-lanceolate, tapering gradually to apex, mostly 3–3.5 mm long, plane to abaxially keeled, strongle convoluted when dry; costa subpercurrent; apex acute; margins entire, plane, bistratose in apical half or more, without a distinct border; cells in apical half quadrate to shortly rectangular, 7–12 μm long, 6–10 μm wide, unistatose or bistratose in longitudinal rows or patches; cells near base rectangular 28–58 μm long, 7–10 μm wide. Seta 2.5–3.5 mm long, yellow or yellow-brown. Capsules oblong-ovoid, c. 1.7 mm long. Operculum c. 1 mm long, rostrate or obliquely rostrate.