The stems are sharply triangular and leafy, growing to a height of 2 m. Leaf blades are 8-12 mm. The spikelets are 10-25 mm. Nutlets are 4- 5 mm. In flower from July to September. It is a common dominant in Mississippi River backwaters.
River bulrush is a favorite food of muskrats.
Wildlife values are similar to those described for other bulrushes.