鳞根萍 lin gen ping

Fronds free floating on water surface, 1-8 coherent in one small group, without green stalk at base (but with a thin white stipe connecting fronds), shiny green, sometimes with reddish spots on upper surface, red on lower surface (always deeper red on lower surface than on upper), obovate, 1.5-4 mm, 1-1.5 × as long as wide, flat, with distinct papillae on midline of upper surface, margin entire, base rounded; veins 3, nearly reaching apex, greatest distance between lateral veins near or distal to middle, lateral veins outcurved medially. Root 0.5-15 cm, sheath not winged, apex rounded (to pointed). Turions often present, rootless, olive-brown, 0.5-1.5 mm. Ovary with 1 ovule; utricular scale with narrow opening at apex. Fruit not winged toward apex. Seed with 30-60 indistinct ribs. Fl. (rare) Jun-Sep. 2n = 40, 42, 50, 80.

Lakesides, spring pools, ponds, slow-flowing streams; in regions with continental cool-temperate climate; sea level to 3000 m. Anhui, Hebei, Heilongjiang, Nei Mongol [N Japan, Korea, Mongolia, Russia; C and SW Asia, North America; introduced in Europe].