Tassel Stonewort Tolypella intricata

Stoneworts are a very ancient group of aquatic plants: they are complex algae that look similar to higher plants. It is yellowish-green in colour and is often encrusted with chalky deposits giving it a crusty feel. Image: Walter Wimmer (iNaturalist).

Find out more: iNaturalist, Plantlife, Freshwater Habitats Trust