Hypoxylon fuscum  

Anamorph Virgariella-like. colonies buff to honey-coloured, velvety, occurring at first stages of stromatal development, more rarely on old stromata. Conidiogenous cells 20-25 x 2-2.5 µm, hyaline, smooth. Conidia 3.5-5.5 x 2-3.5 µm, ellipsoidal, hyaline, aseptate, smooth-walled.
Teleomorph: stromata pulvinate on bark, rounded, at times coalescent, 2-5 mm diam x 0.5-2 mm thick, or effused-pulvinate on decorticated wood, 15-60 mm long x 3-10 mm broad x 0.4-2 mm thick, with inconspicuous perithecial mounds; surface vinaceous purple or vinaceous brown, at times wrinkled between perithecial mounds, with yellowish granules beneath surface with greenish to olivaceous KOH-extractable pigments, the tissue below the perithecial layer brown to dark brown, 0.1-1.5 mm thick. Ascomata perithecia, 200-380 µm diam x 250-400(-600) µm high,  globose to obovoid. Ostioles lower than the stromatal surface, sometimes surrounded by a ring of a white crystalline substance 40-60 µm diam. on mature stromata. Interascal tissue composed of unbranched paraphyses. Asci 105-170 µm total length x 7-10 (-13) µm diam., the spore-bearing parts 65-108 µm long, the stipes 35-90 µm long, fairly thick-walled but not fissitunicate, the apical ring discoid, 0.8-1.5 µm high x 2.8-3.5 µm diam., staining blue in iodine; 8-spored. Ascospores uniseriately or infrequently biseriately arranged, 11-16 x 5-8 µm, ellipsoid-inequilateral with narrowly rounded ends, brown to dark brown, with a slightly sigmoid spore-length germ slit, epispore dehiscent in 10% KOH, smooth, without a gelatinous sheath or appendages.