Phaeoseptaceae S. Boonmee, Thambugala & K.D. Hyde, Mycosphere 9(2): 323 (2018).
MycoBank number: MB 554385; Index Fungorum number: IF 554385; Facesoffungi number: FoF 04462, 8 species.
Saprobic on dead wood in aquatic habitats. Sexual morph: Ascomata erumpent when mature, visible as black spots on the host surface, solitary, scattered, globose to subglobose, dark brown to black, with or without a pseudoclypeus, short papillate, with an apical ostiole. Peridium comprising several layers, outer layers dark brown to black, flattened cells of textura angularis; inner layers hyaline to lightly pigmented cells of textura angularis. Hamathecium comprising cylindrical, branched, septate, anastomosed, cellular pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical- clavate, long pedicellate, with a small ocular chamber. Ascospores 2–(-3)-seriate, cylindrical, broadly fusoid to broadly tapering towards the rounded ends, slightly curved, ends asymmetrical, slightly wider at median part, rounded at both ends, light brown, muriform, allantoid, with multi- transverse septa, and 1 longitudinal septum in each cell, sometimes with 2 longitudinal septa, constricted and darkened at the septa, smooth-walled (adapted from Zhang et al. 2013c, Hyde et al. 2018, Phukhamsakda et al. 2019a). Asexual morph: Hyphomycetous. Pleopunctum. Mycelium immersed in the substratum, composed of septate, branched, subhyaline to greyish brown hyphae. Conidiophores macronematous, mononematous, cylindrical, branched, medium brown, septate, smooth- and thick-walled. Conidiogenous cells monoblastic, cylindrical, brown. Conidia acrogenous, solitary, broadly oval to ellipsoidal, pale brown when immature, broadly obtuse at apex and dark brown, truncate at base and paler brown when mature, often with a hyaline, elliptical to globose basal cell, muriform, constricted at septa, smooth-walled (adapted from Liu et al. 2019b).
Type – Phaeoseptum Ying Zhang, J. Fourn. & K.D. Hyde, in Zhang, Fournier, Phookamsak, Bahkali & Hyde, Mycologia 105(3): 606 (2013).
Notes – Phaeoseptaceae was established in Pleosporales by Hyde et al. (2018) based on Phaeoseptum which was previously placed in Halotthiaceae (Zhang et al. 2013c). Hyde et al. (2018) accommodated Lignosphaeria Boonmee et al., Neolophiostoma, Decaisnella formosa and Thyridaria macrostomoides, in Phaeoseptaceae. Recently Pleopunctum has been introduced to Phaeoseptaceae (Liu et al. 2019b). Liu et al. (2019a) found the monotypic genus Neolophiostoma formed a clade within Halotthiaceae (Ariyawansa et al. 2015a, Hyde et al. 2016, Phukhamsakda et al. 2016). Even though Hyde et al. (2018) have classified Decaisnella formosa and Thyridaria macrostomoides in Pheoseptaceae; they suggested that recollections and epitypification of these species are needed with DNA sequence data in order to ensure correct placement of these two genera (Abdel-Wahab & Jones 2003, Mugambi & Huhndorf 2009b). Lignosphaeria was introduced by Thambugala et al. (2015b), and phylogenetically it formed a sister clade to Thyridaria with a good support. However, Thambugala et al. (2015b) treated Lignosphaeria in Dothideomycetes, genera incertae sedis. This was followed by Pem et al. (2019c). Decaisnella and Thyridaria are retained in Lophiostomataceae and Thyridaceae, respectively. Therefore, we only accept Phaeoseptum and Pleopunctum in Phaeoseptaceae.