On dead wood of Cytisus scoparius I found a group of tiny apothecia. Does anyone recognizes this species or is familiar with the group in which this species should be found?

Apothecia young barrel-shaped, dark brown and with a white flaky edge around the opening, older cup-shaped, up to 0.5 mm diam., dark brown with still the white edge present, sessile, base broadly attached to the substrate, base blackish brown, hymenium grey when young, older yellowish grey.
Spores 12,5-14,3 x 4,4-5,2 (10 spores meassured),
Asci 87-107x8,-9,5 ?m. J-, with clamps,
Paraphyses thread-like, septated, sometimes splitting, upto 2 ?m diam.
Excipulum composed of (only?) brown, globose thick-walled cells, towards de margin transitioning into hyphae, but I don't know whether this means the apothecia have marginal hairs,
The white flakes consist of microscopically small grains which release immediately in water.