Ischyrodon

Dioicous. Silky mats on rocks. Stems creeping or curving upwards from substrate, simple or irregularly pinnate to bipinnate, with rhizoids clustered at leaf bases and developed on bases of adaxial costae. Leaves ovate-lanceolate or lanceolate, erect-spreading when moist, erect when dry; apex acuminate, sometimes piliferous; costa single, strong throughout, extending to c. 3/4 leaf length; margins entire or finely denticulate near apex, plane or weakly reflexed at base on one or both sides; laminal cells linear to elongate-rhomboidal, smooth; alar cells clearly differentiated, oblate, quadrate or rhomboid, extending highest along margin and occupying entire basal region including a short extent along costa. Capsule erect, straight, ellipsoid. Calyptra cucullate, smooth, glabrous. Operculum short-rostrate. Peristome single, of 16 entire exostome teeth fused at base into pairs, sometimes with patches of preperistome attached to basal half of outer face.