Lophium Fr., Observ. mycol. (Havniae) 2: 345 (1818).
Index Fungorum number: IF 2936; Facesoffungi number: FoF 08103, 6 morphological species (Species Fungorum 2022), 4 species with molecular data.
Saprobic on host. Sexual morph: Ascomata hysterothecial, conchate seated upright on bark or erumpent through cracks in bark, scattered or clustered, laterally flattened and often striate, usually axe-head shaped (dolabriform), somewhat tapering towards base, with a long slit-like ostiolum along the ± sharp upper edge, brittle and black. Asci cylindrical, bitunicate, short stiped, containing 8 spirally entwined spores. Paraphysoids branched, anastomosing, septate and hyaline. Ascospores filiform, tapered at ends, multiseptate with septa at intervals of mostly 5–8 µm, yellowish hyaline, gradually becoming spirally arranged within the ascus. Asexual morph: Unknown (adapted from Fries 1818; Vasilyeva 2001; Mathiassen et al. 2014).
Type species: Lophium mytilinum (Pers.) Fr.
Notes: Lophium is characterised by conchate hysterothecia seated on a foot-like base or sessile openly on the substrate, scleroparenchymatous peridium, trabeculate pseudoparaphyses, elongate asci bearing one fascicle of transversely septate filiform ascospores, frequently spirally arranged. Zogg (1962) added two species L. elegans and L. mayorii. Lophium differs from other genera in Mytilinidiaceae in having conchate, solitary to gregarious ascomata which never form fused, ridge-like, assemblages (Hyde et al. 2013). In the phylogenetic analysis of Boehm et al. (2009), L. mytilinum is closely related to Quasiconcha. Lophium differs from Quasiconcha in having filiform ascospores while species of Quasiconcha has reticulated didymospores. Lophium is morphologically and phylogenetically a distinct genus in Mytilinidiaceae. Molecular markers available for Lophium are ITS, LSU, SSU, mtSSU, RPB2 and TEF-1.