Glyceria notata
Glyceria notata, the plicate sweet-grass or marked glyceria, is a species of semi-aquatic true grass in the tribe Meliceae. It is from the cosmopolitan genus Glyceria, a genus of tufted, perennial grasses. Its culms are 30–80 cm in height, ascending from a prostrate base, with dark- to bluish-green, flat or folded leaf-blades some 5–30 cm long by 3–14 mm wide.
It is known as invasive in some parts of the world.