Monoblastiaceae Walt. Watson, New Phytologist 28: 106 (1929).
= Eriomycetaceae Huanraluek & Hyde, in Hyde et al., Fungal Diversity 100: 146 (2020).
MycoBank number: MB 81020; Index Fungorum number: IF 81020; Facesoffungi number: FoF 08851; approximately 120 species (this paper).
Lichenized on bark, more rarely on rocks or leaves (supra- or rarely subcuticular), more rarely non-lichenized and saprobic on leaves or bark (Eriomyces, Funbolia, Heleiosa, Pseudopassalora) or hyperparasitic on bracket fungi (Phellinocrescentia); usually in terrestrial, chiefly lowland to montane tropical to subtropical habitats, with few species extending into temperate regions and in one case (Heleiosa) growing on leaves of Juncus in salt marshes. Thallus in lichenized species mostly reduced and ecorticate, white, to distinctly corticate, grey-green to olive brown, sometimes shiny (Megalotremis, Trypetheliopsis), in nonlichenized species absent. Photobiont in lichenized species trentepohlioid. Ascomata when present scattered, clustered, or aggregated, immersed to sessile, mostly black but some- times covered by thallus, rarely non-carbonaceous, globose to pear-shaped or conical, ostiolate, ostiole apical or eccentric, with periphyses. Involucrellum present, sometimes only apically, or reduced, usually dark brown to carbonized, paraplectenchymatous in thin sections. Excipulum dense, consisting of compressed hyphae, appearing prosoplectenchymatous in thin sections but structure sometimes difficult to observe when carbonaceous, hyaline to brown or brownblack. Hamathecium usually comprising 0.5–0.7 µm wide paraphyses (trabeculate pseudoparaphyses according to Harris (1990, 1995), hyaline, straight, branched and anastomosing, rarely (Eriomyces) formed by 1–3 µm wide, branched cellular pseudoparaphyses. Asci (1–)2–8-spored, rarely polyspored (Eriomyces), bitunicate, fissitunicate, mostly cylindrical to sometimes cylindrical-clavate, shortly pedicellate, with narrow to broad, non-amyloid ocular chamber and in part fluorescent ring- or cap-structures. Ascospores uni- to biseriate or irregularly arranged, ellipsoid-oval to oblong or sometimes fusiform, hyaline to rarely brown, aseptate or 1–3-septate, with thin to rather thick (Megalotremis, Trypetheliopsis) eusepta and more or less rectangular lumina, smooth-walled or ornamented or rarely with appendages (Heleiosa), sometimes slightly constricted at the septa, in 1-septate ascospores the upper cell often distinctly larger than the lower cell (particularly in Anisomeridium). Conidiomata common, usually pycnidia, very rarely hyphomycetous (Funbolia, Pseudopassalora); pycnidia immersed to sessile and usually visible as black dots, but sometimes conspicuous and flask-shaped with a short to long a beak or hair-like (Anisomeridium, Caprettia) or asymmetrically cup- or earshaped (campylidiiform: Trypetheliopsis). Conidia acrogenous or rarely pleurogenous (Funbolia), either macro- or microconidia; macroconidia usually aseptate (septate in Funbolia, Pseudopassalora), (globose to) broadly ellipsoid to oblong-bacillar or guttuliform, (2.5–)5–15(–45) × (2–)3–7(–16) µm large, hyaline (brown in Funbolia, Pseudopassalora), often forming clusters embedded in a gelatinous matrix, these clusters in some species in the form of sacci or cirri (Anisomeridium, Caprettia); microconidia aseptate, globose to broadly ellipsoid or fusiform, small, 2–4(–5) × 1–2(–4) µm large, hyaline.
Chemistry: Most species do not contain secondary substances; lichexanthone and anthraquinone pigments are known from a few taxa.
Type: Monoblastia Riddle.
Notes: For a detailed discussion of the lichenized core group of the family (Acrocordia, Anisomeridium, Caprettia, Megalotremis, Monoblastia, Trypetheliopsis), including a critical review of the currently applied genus concept, see Lücking et al. in Hyde et al. (2013). The scarce molecular data available support monophyly of Megalotremis and a close relationship of the latter with Trypetheliopsis, while Anisomeridium is likely polyphyletic (Fig. 49), a notion anticipated by Harris (1995). Representatives of all genera except Caprettia and the type genus, Monoblastia, have been sequenced, so the position of Caprettia within the family, based on hamathecium and ascus structure, ascospore type, and the peculiar conidiomata and conidia, remains tentative. The accurcate circumscription of the family hinges on the presumed close relationship of Monoblastia with e.g. Acrocordia, and so far only a single species of the latter has been sequenced. The taxonomic delimitation between Ani- someridium, Megalotremis, and Trypetheliopsis is discussed in detail below.
Fig. 49 Best-scoring maximum likelihood tree of currently available data in Monoblas- tiales and its only family, Monoblastiaceae (including Eriomycetaceae), based on a combined alignment of five markers (nuSSU, nuLSU, ITS, mtSSU, TEF1α), with a length of 3612 bases (single autapo- morphic base calls in gappy sites removed). The tree was reconstructed using the univer- sal GTR-Gamma model without site partitioning, and the final likelihood was − 10218.109712