Aquatic or wetland perennial herbs. Leaves petiolate; leaf-blades linear, elliptic or ovate, acute, rounded, truncate or cordate at base, entire to crenate-dentate, erect and more or less isolateral or floating and then strongly dorsiventral, glossy or darker green above, matt and dotted beneath. Inflorescence an erect open to compact panicle. Flowers homostylous or heterostylous, pedicellate; corolla yellow or white, conspicuously fimbriate at the throat, rarely woolly or hairy over entire inner surface, lobes without a longitudinal keel on inner surface, margins entire or serrulate; ovules 11 or more per placenta. Capsule ellipsoid, ovoid, globular or urceolate, opening by 4 apical valves, ripening in the air; seeds ellipsoid, without a conspicuous caruncle.
An endemic Australian genus of 7 species.