8. Pistia L., Sp. Pl. 2: 963 (1753).
By: Himanchal T. Magar & Mohan Siwakoti
Taxon Description
Floating stoloniferous aquatic herbs. Roots many, feathery. Leaves in rosettes, obovate, obcuneate or obcordate, densely hairy; primary veins parallel, rib-like, secondary veins reticulate. Inflorescences small, solitary, smaller than leaf, hidden in leaf bases. Peduncles extremely reduced, pubescent. Spathe constricted centrally, hairy outside, tubular below; blade whitish, short, suborbicular, free margins between tube and blade folded between stigma and male organs. Spadix almost equaling spathe, mostly adnate to spathe; lower part consisting of a single ovary fused on back to spathe, male section a single ring of stamens borne on short stipe subtended by green corona; male flower a synandrium consisting of 2 connate stamens. Flowers unisexual, naked, perianth absent. Gynoecium obliquely attached with the spadix axis; ovary ovoid, 1-loculed with numerous ovules; style attenuate, incurved toward male flowers; stigma disciform; placenta parietal. Fruit an ellipsoid berry. Seeds barrel-shaped, endosperm copious.
Taxon Statistics
Worldwide one species, distributed in tropical and subtropical regions, including Nepal.
1. Pistia stratiotes L.; Sp. Pl.: 963 (1753).
Pistia occidentalis Blum.
कुम्भिका Kumbhika (Nepali).
Aquatic, free-floating, stoloniferous herbs, 10–15 cm. Roots multiple, feathery, hanging below water surface. Leaves several, arranged in rosettes, petioles green, very short and inconspicuous; leaf blade obovate, obcuneate or obcordate, 1.3–10 X 1.5–6 cm, green, densely hairy, base sharply cuneate, apex truncate or retuse. Peduncles extremely reduced, pubescent, 5–7 mm. Spathe white or grayish white, pubescent, 5–12 mm; limb ovate, apex truncate. Spadix almost equaling spathe, mostly adnate to spathe, male zone with a single ring of stamens borne on short stipe subtended by green corona.
Distribution: Nepal, W Himalaya, E Himalaya, Assam-Burma, S Asia and S W Asia; Africa.
Altitudinal range: 200–600 m.
Ecology: Aquatic, free-floating, lakes, ponds, stagnant water.
Flowering: May–November. Fruiting: NA.
It is used as medicine, green manure in Eastern Nepal (Niroula & Singh 2010).