Hello Everyone,

I have found some grey perithecia immersed beneath the epidermis of a dead stem of Glyceria maxima. Areas of the stem look quite grey from the fruit bodies, each with a clypeus surrounding it.

I guess that the fruit bodies are not fully mature, because of the colour of the perithecia and the hyaline spores, either with one large, central guttule or filled with many smaller guttules. Assuming, of course, that I have suggested the correct genus. 

The photo of the fruit bodies and a sketch of the microscopy are attached.

I can not identify a species which would grow on Glyceria. I wonder if anyone can assist?

Thank you,
With Best Wishes,
Peter.