Angustospora Abdel-Aziz, Fungal Divers. 78: 54 (2016).
Index Fungorum number: IF 551714; Facesoffungi number: FoF 01632, 1 morphological species (Species Fungorum 2021), 1 species with molecular data.
Saprobic on decayed wood in freshwater habitats. Sexual morph: Ascomata globose to subglobose, immersed to erumpent, solitary, ostiolate, papillate, periphysate, coriaceous to sub-carbonaceous, dark-brown to black. Peridium comprising two strata, outer stratum dark-brown to black, forming a textura angularis, inner stratum comprising hyaline, thick-walled, flattened cells arranged in a textura angularis. Hamathecium comprising numerous, 1–2.5 μm wide, distantly septate, branched, trabeculate pseudoparaphyses, within a gelatinous matrix, anastmosing above asci. Asci 8-spored, bitunicate, fissitunicate, clavate, short pedicellate, apically rounded, with a wide, shallow ocular chamber and faint ring. Ascospores overlapping biseriate, dark-brown to black, (3)– 5– (7) septate, polar cells lighter when young and apical cells with two-walls, surrounded by thin, gelatinous, striate layer. Asexual morph: Unknown (adapted from Li et al. 2016).
Type species: Angustospora nilensis Abdel-Aziz
Notes: Angustospora is characterised by globose to subglobose ascomata, fissitunicate, clavate asci, and overlapping biseriate, dark-brown to black ascospores. Angustospora resembles Caryospora in having large ascospores with a median septum and added septa near poles of the ascospores. Angustospora differs from Caryospora in having small ascomata and 8-spored, clavate asci (Barr 1979b; 1990; Hawksworth 1982; Abdel-Wahab and Jones 2000; Raja and Shearer 2008; Zhao and Zhao 2012; Ariyawansa et al. 2015b). Angustospora was placed in Testudinaceae based on phylogenetic analyses of SSU and LSU sequence data (Li et al. 2016). Angustospora is a distinct and well-supported genus in Testudinaceae. Molecular markers available for Angustospora are LSU, SSU, RPB2 and TEF-1.