Lemna species - Duckweeds

Lemna trisulca - Ivy-leaved Duckweed is easiest to identify.

Lemna gibba - Fat Duckweed. This is thought to be the commonest dickweed, but is often mistaken for Lemna minor. It is broadest near the obliquely asymmetric bluntly-rounded apex. The lacuna can be seen by holding up to the light. Later in the season it thickens and may turn red above and sometimes below. Often found with lots of small, unidentifiable, smaller plants.

Lemna minor - Common Duckweed is rounded rectangular widest near the middle. There are no lacuna, it can redden underneath later in the season.

Lemna minuta - Least Duckweed. Small duckweed maybe juvenile plants. However minuta is grey-green and translucent symmetrical ellipses.