Pillwort Pilularia globulifera

This tiny plant is a type of creeping fern. It is hard to spot because it has thin, grass-like leaves and often grows with water grasses or small rushes. The ‘pills’ are tiny round spore cases at the bases of the stems. Image: Len Worthington (Flickr).

Find out more: iNaturalist, Plantlife, Online Atlas of the British and Irish Flora