Nymphoides parvifolia

Annual or perennial, rhizomatous herbs; rhizome short, obconical. Branches all fertile, very slender, petiole-like, uniphyllous, 8-20 cm long. Leaves dimorphic; sterile leaves many, in a basal rosette, submerged; petiole 2-4 cm long, often winged; lamina spathulate, to 3 cm x 1.5 cm; fertile leaves solitary at the apices of capilliform branches, floating, ovate-orbicular, rounded or obtuse at apex, deeply cordate at base with narrow sinuses, to 4 cm x 3 cm, membranous, entire, green; petiole 2-5 mm long. Flowers bisexual, homostylous in umbellate clusters of 4-8 at the junction of the petiole and the branches. Calyx deeply 4(-5) lobed; lobes oblong-acute, to 2 mm x 1 mm, pinkish at apex, hyaline at margin. Corolla white with a yellow throat; tube 2-3 mm, with a ring of hyaline hairs at the throat; lobes 4 (-5), oblong or elliptic, 3-5 mm long, margins fimbriately toothed towards the apex. Stamens as many as corolla lobes, inserted below the throat; filaments 1-1.5 mm long, alternating with minute, stalked tufts of white, glandular hairs. Pistil bottle-shaped with 4-5 disc glands below; style short, but distinct; stigma bilobed. Capsules ellipsoid, apiculate, torulose when ripe, longer than the fruiting calyx; seeds 8-15 in each capsule, light brown, discoid, to 1 mm across; surface tuberculate; testa cells foveolate with sinuate and faintly raised junctures.

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References:
Catalogue of Life  The Plant List Ver.1.1  IPNI GBIF (with type specimens) India Biodiversity Portal  IUCN Red List (LC)