Often mistaken for grass, the UK's sole native aquatic fern and internationally recognised as being endangered, Pilularia globulifera forms a lush green carpet around pond margins. Its thin, grass-like leaves, resembling strands of vibrant green hair, emerge from long, slender rhizomes, notable by the pill-like spore-producing structures at its base. Ideal for the periphery of ponds and pools with seasonal water level changes, this plant excels in marshy terrain, making it a valuable addition to boggy ground. Unsuited to shade or water pollution, it thrives in open, unpolluted environments, where it can spread its verdant charm along the edges of fluctuating water bodies.