Xylariaceae Tul. & C. Tul., Select. fung. carpol. (Paris) 2: 3 (1863)

Index Fungorum number: IF 81528; MycoBank number: MB 81528Facesoffungi number: FoF 00070; 1236 species.

Saprobic, pathogenic, or endophytic in wood, leaves, and fruits, or associated with insect vectors. Sexual morph: Stromata extremely variable in size, shape, and colour, erect or applanate or effuse-pulvinate, or sometimes rudimentary or lacking, arising singly or aggregated, with one to several ascomata, ostiolate, mostly without extractable stromal pigments, unipartite or bipartite. Ascomata variable in size, globose-pyriform, single or multi-layered. Ostioles papillate, umbilicate or at the same level as the stromal surface. Paraphyses hyaline, filamentous, septate, embedded in a gelatinous matrix. Asci 4–8-spored, unitunicate, cylindrical to clavate, pedicellate or apedicellate, apically rounded, with or without a J+, apical ring, or with apical thickenings. Ascospores uniseriate-biseriate, brown to black, rarely hyaline, 1–2-celled, variously-shaped, mostly ellipsoidal, subglobose or reniform, mostly with a germ slit, straight, spiral or sigmoid. Perispore dehiscent or lacking, smooth or with patterns. Asexual morph: Hyphomycetous. Mostly geniculosporium-like. Conidiophores hyaline to light brown, smooth, branched. Conidia hyaline, roughened or smooth, ellipsoidal. Several hyphomycetous genera have been linked to Xylariaceae (adapted from Maharachchikumbura et al. 2016b, Daranagama et al. 2018).

Type genusXylaria Hill ex Schrank

Notes – Maharachchikumbura et al. (2016b) accepted 87 genera with a complete family description of Xylariaceae, which included the subfamilies Xylaroideae and Hypoxyloideae. Wendt et al. (2018) re-established Hypoxylaceae (Hypoxyloideae) based on morphology, phylogeny and secondary metabolite analyses. Based on morphology, phylogeny and molecular clock analyses, Clypeosphaeriaceae was synonymized under Xylariaceae with a stem age of 63 MYA (Jaklitsch et al. 2016b, Hongsanan et al. 2017). However, in present study, we accept Clypeosphaeriaceae as a distinct family (see notes under Clypeosphaeriaceae). Daranagama et al. (2018) provided an updated account of genera of Xylariaceae accepting 37 genera after observing type specimens. However, Wendt et al. (2018) placed Gigantospora, Nipicola, Sabalicola, Spirodecospora, Striatodecospora and Xylotumulus in Xylariales genera incertae sedis, due to lack of molecular data and undetermined asexual morphs. We accept those genera in the Xylariaceae based on study of herbarium specimens by Daranagama et al. (2018). Lee et al. (2016) and Johnston et al. (2016) introduced Abieticola and Entalbostroma in Xylariaceae. Wijayawardene et al. (2017a) validly published the genus Palmaria in Xylariaceae due to invalid nomenclature as Palmomyces (Hyde et al. 1998a). Following recent updates, we accept 32 genera in Xylariaceae.

Xylariaceae species are important producers of bioactive compounds and secondary metabolites (Stadler & Hellwig 2005, Helaly et al. 2018). Song et al. (2014) summarized 188 secondary metabolites with bioactive properties produced by Xylaria species. Since the taxa presently included under Xylaria are not well-resolved, secondary metabolites may be possible markers for species identification (Lee et al. 2000, Song et al. 2014). Isaka et al. (2012) described novel secondary metabolites from Poronia gigantea, and suggested that poronitin A (1) and (R)-5- methylmellein as useful chemotaxonomic markers for this genus. There are several other xylariaceous genera such as Coniolariella, Entoleuca, Hypocopra, Kretzschmaria, Rosellinia and Xylotumulus that have been subjected to secondary metabolites analyses (Stadler et al. 2001, Stadler & Hellwig 2005, Helaly et al. 2018). Therefore, it is important to extend the morphology, phylogeny and chemotaxonomy approaches to discover relationships in Xylariaceae (Helaly et al. 2018).