Lemna trisulca L.

FRONDS: Fronds 3-50 coher together and very often form branched chains, 3-15 mm long (without stalk), 1-5 mm wide, 2-3 1/2 times as long as wide; stalk 2-20 mm long; no distinct turions which sink individually to the bottom of the water present. INFLORESCENCE/INFRUCTESCENCE: Plants occasionally flowering and rarely fruiting. Fruit symmetrical, 0.6-0.9 mm long, 0.7-1.2 mm wide; winged margin about 0.15 mm wide; style about 0.15 mm long; seed 0.6-1.1 mm long, 0.5-0.8 mm thick, with 12-18 distinct ribs.