Hypoxylaceae DC. Fl. franc¸., Edn 3 (Paris) 2: 280 (1805)
Index Fungorum number: IF 81885; MycoBank number: MB 81885; Facesoffungi number: FoF 02979; 422 species.
Saprobic or endophytic in wood, leaves and fruits, sometimes symbiotically associated with insect vectors in terrestrial and aquatic habitats (Pažoutová et al. 2010, 2013). Sexual morph: Stromata (if present) erect, glomerate, pulvinate, discoid, effused-pulvinate, hemispherical, spherical or peltate, or sometimes rudimentary or lacking, arising singly or aggregated into groups, with one to several ascomata, surface colour variable, mostly black-brown, ostiolate, mostly with extractable stromal pigments, unipartite, attached to the surface by broad bases, conical-dome shaped, raised areas. Ascomata variable in size and shape, globose-subglobose or elongate cylindrical-pyriform, embedded in the stroma, monostichous, interior sometimes zonate or filled with liquid. Ostiole papillate or umbilicate or at the same level as the stromal surface, with or without discs. Paraphyses hyaline, filamentous, septate, embedded in a gelatinous matrix, usually longer than the asci. Asci 4–8-spored, unitunicate, cylindrical to clavate, rarely globose, pedicellate or apedicellate, apically rounded, with or without a J+, or J-, apical ring, or with apical thickenings. Ascospores uniseriate-biseriate (crowded in Phylacia and Pyrenomyxa), uni-bicellular, ellipsoidal- subglobose, brown to black, rarely hyaline, mostly with a germ slit, straight, spiral or sigmoid, sometimes with rostrate, hyaline dwarf cell. Perispore dehiscent or sometimes lacking, smooth or with patterns. Asexual morph: Conidiophores mostly nodulisporium-like, hyaline to light brown, smooth, branched, mononematous or infrequently synnematous, usually macronematous. Conidiogenous cells cylindrical, usually hyaline, one to several on each branch of the conidiophore, swollen apex. Conidia hyaline, roughened or smooth, ellipsoidal (adapted from Wendt et al. 2018).
Type genus – Hypoxylon Bull.
Notes – The term Hypoxylaceae was not used in modern classifications until 2017 and treated under Xylariaceae (as ‘Hypoxyloideae’). Wendt et al. (2018) validated the family in the Xylariales based on multi-locus phylogeny, morphology and chemotaxonomy studies. Molecular clock evidence confirmed the familial position of Hypoxylaceae within Xylariales (Hongsanan et al. 2017). Daranagama et al. (2018) accepted 18 genera including Alloanthostomella, Neoanthostomella and Pseudoanthostomella in the Hypoxylaceae. However, according to the phylogenetic studies by Voglmayr et al. (2018) and Wendt et al. (2018), these three genera cluster as a separate clade in Xylariaceae sensu stricto; thus, they are placed in Xylariales genera incertae sedis. Herein, we accept 19 genera in Hypoxylaceae.