Dictyomeridium Aptroot, M.P. Nelsen & Lücking in Lücking et al., Lichenologist 48: 756 (2016).
MycoBank number: MB 816873; Index Fungorum number: IF 816873; Facesoffungi number: FoF 08796; seven morphologically defined species (Aptroot and Lücking 2016); molecular data available for one species (Lücking et al. 2016).
Lichenized on bark in terrestrial, chiefly lowland to lower montane tropical habitats, typically in drier situations. Thallus ecorticate, usually whitish. Photobiont Trentepohlia. Ascomata solitary to sometimes aggregated, erumpent to prominent, somewhat pyriform when seen from above, brown-black to grey-black, carbonaceous, ostiolate, osti- ole lateral. Involucrellum carbonized. Excipulum prosoplectenchymatous, brownish. Hamathecium comprising 0.5–0.7 µm wide paraphysoids, hyaline, straight, branched and anastomosing, embedded in a gelatinous matrix. Asci 2–8-spored, bitunicate, fissitunicate, clavate, short pedicellate, with a nonamyloid ocular chamber. Ascospores irregularly arranged to biseriate, oblong-ellipsoid, hyaline, often I+ amyloid, muriform, euseptate, smooth-walled, not constricted at the septa, with a gelatinous sheath. Pycnidia known from a few species, immersed to erumpent, visible as black dots. Conidia aseptate, bacillar, hyaline.
Chemistry: lichexanthone sometimes produced on thallus surface.
Type species: Dictyomeridium proponens (Nyl.) Aptroot, M.P. Nelsen & Lücking in Lücking et al., Lichenologist 48): 757 (2016)
Notes: For key and discussion see Aptroot and Lücking (2016).
Species
Dictyomeridium proponens