Lemna valdiviana (Araceae)
Fronds 1-5 mm long, 0.6-3.0 mm wide, 1 1/3-3 times as long as wide, occasionally somewhat pointed, 4-20 coher together, often submerged; air spaces in only 1 layer, rarely extended further to the tip than 2/3 of the distance from the node to the tip (flowering fronds with more extended aerenchymatic tissue); nerve mostly pronounced, longer than the extension of the air spaces or at least running through 3/4 of the distance between the node and the tip; forming mostly a distinct angle with the tract of elongated cells at the base (frond at the base distinctly asymmetric) . Flowers and fruits. Plants occasionally flowering and fruiting. style about 0.2 mm long; fruit 1.0-1.35 mm long, 0.7-0.9 mm wide; seed 0.6- 0.8 mm long, 0.4-0.6 mm thick, with 15-29 ribs.
Rather humid regions of America with oceanic climate (no low winter temperatures).