Fellhanera subtilis (Vezda) Diederich & Sérus.

    Thallus crustose, limited to a small crust, variable in thickness, 0.1-0.5 mm thick, grey-greenish, greenish. Apothecia variable in size, scarce, clustered towards the thallus center, 0.1-0.5 mm diam., disc flat, pale grey-pink slightly hyaline, true exciple thin, paler, finally excluded. Ascopores narrowly fusiform to clavate-fusiform, sometimes slightly curved, 1-(2)-3-spetate, 10-15 x 3,5-5 µm according to our measures. Chemical spot tests negative. Rare or understated, on small branches and twigs of  Buxus, Vaccinium myrtillus, and also on pine needles and twigs of Larix and Picea. This species is very similar to Fellhanera bouteillei that differs by its 1-septate ascospores. N.B. We consider that most of the conditions requested to insure the development of this species in Brittany are satisfied. However, it has not been evidenced yet and, due to the lack of microscope observations of ascospores in order to control the 3-septate criterion,  it probably has been confused with Fellhanera bouteillei