Roots to 15 cm, tip mostly rounded; sheath not winged. Stipes white, thin, often decaying. Fronds floating, 1 or 2--5 or more, coherent in groups, obovate, often gibbous, 1--8 mm, 1--1.5 times as long as wide, margins entire; veins (3--)4--5(--7) (all originating from node), greatest distance between lateral veins near or distal to middle; papillae often indistinct; upper lower surface sometimes red colored, coloring beginning from margin, lower upper surface occasionally with distinct red spots beginning from margins near apex; largest air spaces longer than 0.3 mm; distinct turions absent. Flowers: ovaries (1--)2--7-ovulate, utricular scale with narrow opening at apex. Fruits 0.6--1 mm, laterally winged. Seeds with 8--16 distinct ribs, falling out of fruit wall after ripening. 2n = 40, 42, 44, 50. Flowering (rather frequent) spring--fall. Eutrophic, quiet waters in temperate regions with mild winters; 0--1900 m; Ariz., Calif., Ill., Nebr., Nev., N.Mex., Tex., Wyo.; northern Mexico; South America; Eurasia; Africa; Atlantic Islands.

Plant: Floating aquatic plant Leaves: FRONDS floating on the surface of the water, single or 2 to a few cohering in small groups, obovate, 1-8 mm long, 1-1.5 times as long as wide, often gibbous, without a green stalk but with a very small white stipe that often decays; margins entire; nerves (3-)4-5(-7), the greatest distance between the laterals near or above the middle; distinct papillae absent; upper surface occasionally with distinct red spots; lower surface sometimes red colored, the red coloring beginning from the margins; largest air spaces wider than 0.3 mm; the sheath unwinged, the tips mostly rounded; no distinct turions present Flowers: frequent, 1-7-ovulate, the small utricular scale with a narrow opening at the top Fruit: 0.6-1.0 mm long, laterally winged, with dry pericarp. SEEDS: with 8-16 distinct ribs Misc: -Eutrophic, quiet waters; below 1800 m (6000 ft); Mar-Sep Notes: root up to 15 cm long REFERENCES: Landolt, Elias. 1992. Lemnaceae. Ariz.-Nev. Acad. Sci. 26(1)2.