Lemna trisulca

Lemna trisulca differs from other duckweeds in that it grows largely below the water surface, forming distinctive cross-shaped chains of connected fronds in the water column. It only rises to the surface to flower. This submerged habit makes it considerably less invasive and more suited to planted aquariums where maintaining light for other plants is important. It is also a favoured food for waterfowl and some fish, and its unique underwater growth form makes it botanically interesting.