Herb, floating, aquatic, perennial, stoloniferous, profusely rooting at the nodes; leaves rosette forming, broadly ovate-elliptic, obtuse at apex, rounded-subcordate at base, leathery, shining green on both surfaces; petioles elongate, swollen with fusiform bulbous portion in the middle, spongy; scape simple with conspicuous sheath near middle, racemes many flowered; perianth slightly curved, limbs 2-lipped, 6-fid, violet-blue, upper lobe larger with a patch of blue having yellow spot in centre; stamens-6, inserted in the throat of perianth, unequal, 3-longer and 3-shorter, glandular, pubescent; ovary sessile, 3-celled, ovules many in each locule, style filiform, stigma slightly swollen or shortly 3-6 lobed; capsules ovoid-oblong; seeds ovoid, many, ribbed.