Fungalpedia – Note 2468, Pseudoastrosphaeriella
Pseudoastrosphaeriella Phook., Z.L. Luo & K.D. Hyde
Citation when using this data: Dong W et al. 2020 – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification: Pseudoastrosphaeriellaceae, Pleosporales, Pleosporomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Saprobic on bamboo and palms in freshwater or terrestrial habitats. Sexual morph: Ascostromata dark brown, scattered to gregarious, immersed to erumpent, slightly conical to lenticular or hemisphaerical, with flattened base, uni- to bi-loculate, glabrous, coriaceous, with ostiolate papilla. Ostioles central, cylindrical, brittle, carbonaceous, with short or long neck. Peridium thick-walled, unequal in thickness, composed of pseudoparenchymatous cells, outer layers mostly comprising host cells and fungal tissue, poorly developed at the base. Pseudoparaphyses numerous, trabeculate, filiform, hyaline, branching and anastomosing, embedded in a hyaline gelatinous matrix. Asci 8-spored, bitunicate, clavate to cylindric-clavate, pedicellate, with ocular chamber. Ascospores overlapping uni- to tri-seriate, brown to reddish brown, fusiform to clavate, septate, rough-walled or smooth-walled, with or without striations, or with longitudinal ridges, with or without a mucilaginous sheath (Phookamsak et al. 2015b). Asexual morph: Coelomycetous. Conidiomata pycnidial, immersed, solitary to scattered, conical or hemisphaerical to globose, ostiolate. Peridium thick-walled, unequal in thickness, composed of dark, pseudoparenchymatous cells. Conidiophores reduced. Conidiogenous cells phialidic, discrete, cylindrical or cylindric-clavate or ampulliform, septate, hyaline, smooth-walled. Conidia globose to subglobose, or oblong, aseptate, hyaline, smooth-walled (Phookamsak et al. 2015b).
Notes: Pseudoastrosphaeriella was introduced to accommodate astrosphaeriella-like species (Phookamsak et al. 2015b). Pseudoastrosphaeriella is distinguished from Astrosphaeriella Syd. & P. Syd. by its immersed ascostromata beneath the host epidermis, with short or long necks, and the peridium comprising host cells and fungal tissue. In contrast, Astrosphaeriella has erumpent ascostromata through the host epidermis, with a star-like or rounded flange and small papilla, and the peridium comprising an opaque, black, amorphous, brittle layer (Liu et al. 2011; Phookamsak et al. 2015b). Seven species are accepted in Pseudoastrosphaeriella, five of which are from freshwater habitats. All freshwater Pseudoastrosphaeriella species (see list below), have rough-walled ascospores with minute striations or longitudinal ridges (Phookamsak et al. 2015b), except our new species P. aquatica which has smooth-walled ascospores.
Type species: Pseudoastrosphaeriella thailandensis Phook., Z.L. Luo & K.D. Hyde
Other accepted species: Species Fungorum – search Pseudoastrosphaeriella.
Figure 1 – Pseudoastrosphaeriella aquatica (MFLU 18-0996, holotype). a, b Ascomata immersed with neck erumpent through host substrate. c, d Vertical section of ascomata. e Structure of peridium. f, g Asci embedded in numerous of pseudoparaphyses. h, i Bitunicate asci. j–l Ascospores. m Germinated ascospores. n, o Colony on PDA (up-front, down-reverse). Scale bars: c, d = 100 μm, e = 10 μm, f, g = 30 μm, h, i, m = 50 μm, j–l = 20 μm.
References
Entry by
Wei Dong, Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming 650500, China, Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand, Innovative Agriculture Research Center, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand, Institute of Plant Health, Zhongkai University of Agriculture and Engineering, Haizhu District, Guangzhou 510225, China
Published online 15 May 2026