Aquatic, floating submerged herbs. Stem (stolons) monomorphic, filiform, terete. Leaves very numerous, filiform, with 3-4 primary segments, the secondary segments pinnately divided, each pinna further dichotomously divided into numerous capillary segments with lateral and apical setulae. Bladders dimorphic, stalked, 1-4 mm long, ovoid-subglobose with branched antennae. Inflorescence erect; peduncle filiform, terete, glabrous, without scales. Bracts basifixed. Flowers 5-10; pedicel filiform, much recurved in fruiting. Calyx lobes subequal, ovate with subacute apex. Corolla pale yellow with yellowish brown veins, externally pubescent; upper lip broadly ovate, apex rounded; lower lip elliptic, apex rounded; palate pubescent. Spur cylindrical from a narrowly conical base, longer than wide. Filaments curved. Stigma upper lip ± obsolete; lower lip semicircular. Ovary ovoid. Capsule globose. Seeds disk shaped, narrowly winged.

Fl. Per.: December-April.

Type: India, Koenig s.n. (holo C; iso W).

Distribution: India, South-east Asia from Malaysia, eastwards to China, Japan and North Australia.

A planktonic species which commonly occurs in still and stagnant water of lakes, ponds and rice swamps.