Viridothelium Lücking, M.P. Nelsen & Aptroot, in Lücking et al., Lichenologist 48(6): 758 (2016).
Index Fungorum number: IF 816877; Facesoffungi number: FoF 08826, 11 morphological species (Species Fungorum 2021), 3 species with molecular data.
Thallus corticate, often warted. Sexual morph: Ascomata simple or aggregated in pseudostromata, which can be hardly to clearly raised and are usually not of a different structure and colour from the thallus. Ostioles apical or eccentric, simple or fused. Wall hyphal (textura intricata), usually carbonized. Hamathecium inspersed with oil droplets or not, filaments thin, anastomosing paraphysoids. Ascospores subdistoseptate, with thin walls and only slightly thickened septa, hyaline, I– or weakly I+ violet-blue, transversely septate. Asexual morph: Pycnidia occasionally present (Adapted from Lucking et al. 2016).
Type species: Viridothelium virens (Tuck. ex Michener) Lücking, M.P. Nelsen & Aptroot
Notes: Viridothelium was introduced by Lücking et al. (2016) with V. virens as type species. Viridothelium is characterized by non-astrothelioid, I+ weakly amyloid ascospores (Aptroot & Lücking 2016; Aptroot et al. 2016a, b; Lücking et al. 2016). Viridothelium superficially resembles Astrothelium but is phylogenetically distant. Viridothelium morphologically differs from Astrothelium in having subdistoseptate ascospores resembling those of Trypethelium s. str.