Perfoliate pondweed
Potamogeton perfoliatus. Photo: Joakim Hansen

Its tubers are full of energy

The pondweed produces overwintering tubers just like root vegetable plants (potatoes, cassava etc.). These tubers are full of starch and other nutrients that swans eat in autumn.

Åsa Austin, a PhD student at DEEP aims at understanding the role of aquatic vegetation for ecosystem functioning. She encountered this plant several times during her research. Åsa says that its tubers taste sweet, but a little muddy from the surrounding sediment.

The pondweed can also help small organisms

The pondweed also provides food for other organisms indirectly, explains Åsa. The hair-like algae that are seen growing on the plant in the picture are eaten by small isopods and amphipods such as Gammarus species and Idotea species.

Potamogeton perfoliatus is a resilient plant. Thanks to its long shoots that reach up towards the light, perfoliate pondweed can grow in relatively turbid waters.