The nematode Subanguina graminophila causes galls to form on grasses in the Agrostis (Bent) family. The galls take the form of a purplish or reddish swelling, usually near the base of the leaf blade.

Gall

Ensure you have identified the grass species correctly.

Grassy areas where Agrostis species occur.

Summer.

True status in Britain is difficult to determine due to lack of records.

Status in Leicestershire and Rutland not known.