Calomnion

Dioicous. Asexual propagules absent. Protonema persistent. Mats on tree fern trunks. Stems simple, with rhizoids restricted to near base; central strand present, collapsed in older stems. Mats on tree fern trunks. Leaves complanate, 3-ranked, dimorphic with lateral leaves distinctly differing from ventral rank, becoming larger toward stem apex, scarcely altered when dry; lateral leaves ovate (not in Victoria) or oblong to elliptic-lanceolate or obovate-oblong, patent; ventral leaves orbicular to ovate, smaller than lateral leaves, cordate, appressed and oriented parallel to stem; apex acute, apiculate or acuminate, with (not in Victoria) or without a hairpoint; costa strong, single, subpercurrent, percurrent (not in Victoria) or excurrent (not in Victoria); margins entire to denticulate, plane, without a distinct border; laminal cells polygonal to quadrate throughout or oblate to shortly rectangular near base, smooth; alar cells not differentiated. Acrocarpous. Capsules erect, symmetric, cylindric to fusiform, with an annulus. Calyptra cucullate, ±scabrous above, glabrous. Operculum rostrate. Peristome absent.