Calamagrostis arundinacea is a species of bunch grass in the family Poaceae, native to Eurasia, China and India.

[2] Under its synonym Calamagrostis brachytricha it has gained the Royal Horticultural Society's Award of Garden Merit.

[3] The species is perennial and tufted with short rhizomes and erect culms that are 60–150 centimetres (24–59 in) long.

Each leaf has a truncate ligule which is 2–4 millimetres (0.08–0.16 in) long, and obtuse.

Flowers have a pair of lodicules and stigmas, and three anthers which are 2.4–2.7 mm (0.09–0.11 in) long.