Rust Fungus - Puccinia urticata

Puccinia urticata is a rust fungus which causes galls on the stems and leaves of the alternate host, nettles (Urtica dioica and U urens). The galls are reddish and can be large, causing  considerable swelling and distortion of stem and petioles.  Orange aecia and spermogonia are borne on the swollen areas and leaf undersides. 

The uredinial and telial stages are on the primary plant host, a sedge, and do not cause galls.  Due to small morphological differences in the telial stage, and the range of sedge species used as primary hosts, it may be a complex of species or varieties. 

Common and widespread in Britain.

Fairly common in Leicestershire and Rutland.

See species page on the Bladmineerders website