Fungalpedia – Note 2457, Byssothecium
Byssothecium. Fuckel.
Citation when using this data: Dong W et al. 2020 – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Massarinaceae, Pleosporales, Pleosporomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Saprobic on submerged wood in freshwater or decaying wood in terrestrial habitats. Sexual morph: Ascomata gregarious, erumpent to superficial, uniloculate, subglobose, ovoid to obpyriform, black, coriaceous, with a central ostiolate papilla. Peridium composed of brown, rectangle, pseudoparenchymatous cells, somewhat thinner at base. Pseudoparaphyses dense, cellular, hypha-like, hyaline, septate, embedded in a gelatinous matrix, anastomosing between and above the asci. Asci 8-spored, bitunicate, fissitunicate, cylindrical to clavate, pedicellate. Ascospores biseriate at the apex, becoming uniseriate near the base, ellipsoidal to fusiform, straight to slightly curved, hyaline to brown, usually paler at end cells, septate, basically symmetric, smooth to minutely verrucose, thin-walled (Crane et al. 1992; Pem et al. 2019b). Asexual morph: chaetophoma-like (Boise 1983).
Notes: Byssothecium is characterized by ellipsoidal to fusiform, hyaline to brown ascospores usually with bipolar paler cells (Crane et al. 1992; Pem et al. 2019b). The asexual morph of B. circinans was produced in culture and characterized by minute conidiomata, phialidic conidiogenous cells and hyaline, aseptate conidia, which are similar to Chaetophoma (Boise 1983).
Savoryella E.B.G. Jones & R.A. Eaton shares similar morphological characters with Byssothecium in having cylindrical asci, ellipsoidal, 3-septate ascospores with brown central cells and paler end cells (Jones and Eaton 1969; Dayarathne et al. 2019). The ascomata have a long neck in Savoryella, but it is lacking in Byssothecium. Phylogeny separates them in different classes: Byssothecium in Dothideomycetes (Lumbsch and Lindemuth 2001), and Savoryella in Sordariomycetes (Dayarathne et al. 2019)
Type species: Byssothecium circinans Fuckel.
Other accepted species: Species Fungorum – search Byssothecium.
Figure 1 – Byssothecium circinans (Material examined: GERMANY, Sabine, M. Huhndorf, 10 December 1993, G-K 18367). a, b Ascomata on the host surface. c Section of ascoma. d Peridium. e Pseudoparaphyses. f−i Bitunicate asci. j−l Ascospores. Scale bars: b = 200 µm, c = 100 µm, d = 30 µm, e = 5 µm, f−h = 40 µm, i−l = 15 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 22 May 2026