Lophium mytilinum  

Anamorph: Papulaspora-like, with a small-spored Phoma-like morph also reported. Hyphomycetous morph formed as a dark brown mycelial crust on  decorticated wood or the inner surface of loosened dead bark, often overgrowing effete clusters of pycnidia. Conidia formed in compact clusters, olivaceous brown in mass, becoming black on drying. Conidiophores 15-30 x ca 2.5 µm, yellowish, 2- to 4-celled, poorly developed in heavily proliferating clusters. Conidia initially coiled into a ring-like structure, 13-15 x 8-10 µm and 4- to 6-septate, at maturity more complex and irregularly coiled, 16-18 (-24) x 13-15 µm. Conidiomata pycnidial, 250-300 (-400) µm diam., black, papillate, formed in clusters of up to 15, formed of 4-10 layers of thick-walled angular cells, dark brown and opaque externally and hyaline internally. Conidiogenous cells formed directly from the inner wall, 3-4 (-5) x 2-3 µm, proliferating percurrently. Conidia 2-2.5 x 1-1.5 µm, ovoid to suballantoid, hyaline, asepttate, thin-walled, without a gelatinous sheath or appendages.
Teleomorph: ascostromata hysterothecia with an inconspicuous longitudinal slit, 500-750 µm long, 250-300 µm wide, 300-500 µm high, elliptical (sometimes narrowly so) from above, widening upward from a narrow base to a longitudinal ridge when viewed from the side and ± ovate in vertical transverse section, black, smooth, sometimes concentrically striate, superficial, scattered, in no particular alignment. Peridium with side walls thin, brittle, at the base composed of fused interwoven red-brown epidermoidal cells, composed of parallel hyphal tissue above, at the slit margin perpendicular and markedly elongate-parallel, with a layer of interwoven hyaline thin-walled hyphae forming the floor of the cavity. Interascal tissue composed of filiform pseudoparaphyses 1-1.5 µm diam., with rounded ends, hyaline, smooth, sparsely septate, branched and anastomosed, exceeding the asci and plugging the slit when dry. Asci 170-206 x 7-9 µm, cylindrical, tapering to a lobed base, fissitunicate, the apex rounded, I-, 8-spored, arising from croziers and in parallel from the cavity floor. Ascospores 156-190 x 1.5-2 µm, septa 5-8 µm apart hence 20- to 38-septate, remaining straight within the ascus at maturity, filiform, yellowish to pale brown, smooth, not constricted at the septa, without a gelatinous sheath or appendages.