Fusiformiseptospora G.C. Ren & K.D. Hyde, gen. nov.

MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 10702;

Etymology ‒ Name referring to the fusiform septate spores of this genus.

Saprobic on decaying wood. Sexual morph: Ascomata superficial, solitary, scattered, erumpent to immersed, uni-loculate, globose to subglobose, black. Ostiole central. Peridium thick, comprising of 3–5 layers of light brown to brown cells of textura angularis. Hamathecium of sparse, cylindrical, septate, branched, cellular pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, cylindrical-clavate, broad at the median, apically rounded, with short rounded pedicel. Ascospores overlapping 1–2-seriate, pale brown, fusiform, slightly acute at both ends, with 4–5 transversely septa, constricted at the septa, smooth-walled, guttulate. Asexual morph: Undetermined.

Notes ‒ In our phylogenetic analysis, Fusiformiseptospora nested with Alloconiothyrium, Kalmusibambusa, Kalmusia, and Xenocamarosporium (Fig. 1). Multi-loci phylogenetic analyses of Fusiformiseptospora is phylogenetically well-separated from other genera in this family. Morphologically Fusiformiseptospora is distinct from the extant genera (Alloconiothyrium, Kalmusibambusa, Kalmusia, and Xenocamarosporium). It has uni-loculate ascostromata, broad clavate asci, narrow fusiform ascospores with 4–5 transversely septa and guttules whereas Kalmusia species have narrowly ovoid to clavate asci, narrowly ovoid to clavate, 3-septate ascospores, sometimes with 1–2 vertical septa or mucilaginous sheath (Niessl 1872, Liu et al. 2015, Hyde et al. 2020). Kalmusibambusa has multi-loculate, elongated ascostromata, cylindrical asci, ellipsoidal to fusiform, 3-septate ascospores with rounded to acute ends and a wide mucilaginous sheath (Thambugala et al. 2017). Alloconiothyrium and Xenocamarosporium are known only by their asexual morph (Verkley et al. 2014, Crous et al. 2015, 2019b, Ariyawansa et al. 2020), so it is easy to distinguish from Fusiformiseptospora, which is known only by its sexual morph. Therefore, considering the morphological differences and phylogenetic support, we introduce Fusiformiseptospora as a new sexual genus.

Type species – Fusiformiseptospora thailandica G.C. Ren & K.D. Hyde

Species