Dermea cerasi  

Anamorph: conidiomata stromatic, 0.5-2 mm diam. and 0.2-1 mm tall, separate or rarely confluent, pulvinate, erumpent through the bark, pruinose, yellow-brown, multilocular and sometimes convoluted, composed of pale brown intertwined hyphal tissue, the cells becoming angular in the surface layer; ostiole absent, the conidia being released by irregular breakdown of the wall. Conidiophores to 25 µm long and 1.5-2.5 µm diam., branched and septate, the conidiogenous cells forming terminally or laterally below the septa. Conidiogenous cells cylindrical, proliferating percurrently with well-developed periclinal thickening, collarette absent or inconspicuous. Conidia 40-52 (-65) x 2.5-3.5 µm, narrowly falcate, sometimes sigmoid, with a ± median septum, thin- and smooth-walled, without a gelatinous sheath or appendages.
Teleomorph: ascomata apothecia, 1-3 mm diam. and to 1.5 µm tall, erumpent from the conidial stroma, gregarious, separate or sometimes in small clusters, ± sessile or short-stalked, with a plane to undulate margin, at first yellowish-brown and scurfy, eventually black and glabrous, leathery to horny in consistency. Hymenium at first concave, becoming plane or convex, roughened, sometimes cracked, occasionally slightly umbilicate, olivaceous to greenish when moist, margin at first thick and raised, openings of the pycnidial cavities often appearing as yellowish wrinkles around the margin. Interascal tissue of mostly unbranched paraphyses 1.5-2 µm diam., the apices swollen (to ca 4 µm diam.) and adhering to form a yellowish epithecium. Asci (75-) 90-120 (-150) x 10-13 (-15) µm, cylindric-clavate, tapering below into a short stalk, 8-spored. Ascospores irregularly bieriate, (12-) 15-20 (-25) x (4-) 5-7.5 µm, ellipsoidal-fusiform, straight or slightly curved, hyaline to yellowish brown, 0- to 3-septate.