Apothecia are formed on the stems and the undersides of old leaves of Galium species, including Woodruff (Galium odoratum).  Initially these are pale and globular, then dark brown and saucer-shaped, up to 1mm diameter, and embedded in the host plant tissue.  The asci are long and thin. 

host

Photograph apothecia on host plant; ensure you have noted the host species in your comments.  Microscopic examination may be needed to confirm your record, and we recommend that a specimen is examined by an expert before submission to NatureSpot.

on Galium species

not known; rarely recorded

See Plant Parasites of Europe webpage