Duckweed
Lemna minor L.

Origin: Native

Background
Duckweeds are among the world’s smallest flowering plants. Individual lesser duckweed plants are tiny, round, bright green disks, each with a single root. They are found scattered among emergent plants or massed together in floating mats. Star duckweed is much less commonly observed. Individual nonflowering plants are longer and narrower than lesser duckweed, commonly floating in masses beneath the water surface. Flowering plants more closely resemble lesser duckweed.

Description
Minute, floating perennial herb; plant bodies solitary or few-clustered, orbicular to elliptic-obovate, 1/16" - 3/16" long.