Puccinia obscura is a rust fungus affecting Wood-rushes (Luzula), the primary host.  Light brown uredinia and dark brown telia are formed, but do not cause galls.

The alternate host is Daisy (Bellis) species.  On Daisy, the leaves develop purple-brown patches with spermogonia and aecia, and are gall-causers

Puccinia distincta also causes galls on Daisy

Luzula Bellis

Photograph the rust on the host.  Ensure you have noted the host-plant species in your comments.  If you are recording the aecial stage on Bellis (daisy), microscopic examination will be needed

Alternating generations between Woodrushes (Luzula) and Daisies (Bellis)