Description: Thallus not evident, not lichenized, the hyphae immersed in the thallus of Solorina saccata, discolouring its thallus. Perithecia black to dark brown, 0.2-0.6 mm across, with a central ostiole, immersed for c. 2/3 in the thallus of the host. Exciple of several layers of angular, pseudoparenchymatous, radially compressed, thick-walled cells of textura angularis, reddish to dark brown; hamathecium of branched and anastomosing pseudoparaphyses, the hymenial gel I-. Asci 8-spored, bitunicate, elongate-clavate to short-cylindrical, shortly pedicellate, with a thick-walled apex and a small, sometimes indistinct, ocular chamber. Ascospores at first mainly 3-5-septate, then submuriform, initially pale yellowish to pale brown, becoming brown to dark brown, ellipsoid to fusiform, slightly constricted at the level of the median septum, 18-28 x 8-11 μm, without a visible perispore. Photobiont absent or chlorococcoid. Chemistry: without lichen substances.
Note: an arctic-alpine lichenicolous fungus growing on the thalli of Solorina, more rarely of Peltigera, near or above treeline. The infection usually suppresses the development of ascomata in the host, so that the infested thalli are often sterile.
Growth form: Lichenicolous fungus
Substrata: soil, terricolous mosses, and plant debris