Minute or small, thalloid, free floating, annual herbs; rootless or with capillary roots; root-sheath appendaged, acute root cap; propagates by budding or by hibernating bulbils, rarely by seeds; fronds with two lateral wings, asymmetrical, ovate or obovate to oblong, nearly flat on both surfaces, about 5 x 3 mm in size, thin, obtuse or slightly acute at apex, entire, nerves-3 (sometimes indistinct), daughter fronds budding from lateral pockets; floral pocket lateral or ventral with spathe enclosing 1-pistillate and 2-staminate flowers; perianth absent; stamens 1-2, anthers 1 or 2 celled; pistillate flower-1, style short, stigma truncate or concave; ovary 1-celled with solitary ovule; urticles, ellipsoid, ovoid or bottle shaped; seed-1, laterally compressed, ribbed, albuminous.