Large, densely tufted plant to 120 cm tall. Leaves to 5mm wide with strong parallel ridges and furrows on the upper side. Panicles with whorled spreading branches.

The panicle is branched. Each spikelet contains two florets. A strongly tufted grass forming large tussocks. Its leaves are very rough.

Wet or marshy ground, wet woodland, and heavy soils.

June to August.

Perennia.

Very common throughout Britain.

Very common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 589 of the 617 tetrads.