Rhizomatous plant, forming dense patches, with stiff erect stems, often curved, and a stem leaf.  The leaf is virtually hollow with transverse septa which can be felt as ridges across the leaf, but other species share this character.   It is very similar to Jointed Rush (Juncus articulatus), and they do hybridise; according to Stace (4th edn.) the hybrid can be commoner than either species.   

Inflorescences are larger and more branched than J articulatus, and the mature flowers have brown outer tepals that are acuminate with erect points, usually recurved to some degree.  (reference: Stace, 4th edition)

Jointed Rush is very similar and hybrids occur.  

It may not be possible to identify this from a photo, especially immature or old plants; and be aware of the possibility of hybrids.  Photos showing details of mature inflorescence.   Refer to Stace 4th edition for more information.

Wet meadows and marshy places.

July to September.

Perennial.

Frequent throughout Britain.

Fairly frequent in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 116 of the 617 tetrads.