Fungalpedia – Note 541, Byssotrema
Byssotrema M. Cáceres, Aptroot & Lücking
Citation when using this data: Tibpromma et al. 2024 (in prep.) – Fungalpedia, Lichenicolous fungi.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1
Classification: Graphidaceae, Ostropales, Ostropomycetidae, Lecanoromycetes, Pezizomycotina, Ascomycota, Fungi.
Byssotrema was introduced by Cáceres (2014) within Graphidaceae, Ostropales in Lecanoromycetes with the type species Byssotrema mirabile. This genus differs from Glaucotrema by its extremely uncommon ascoma morphology: the widely open ascomata are more robust and have a largely carbonized excipulum (Rivas Plata et al. 2012, Caceres et al. 2014). Morphological characteristics of Byssotrema having corticolous thallus, epiperidermal, thick, continuous; surface smooth, greenish grey; prothallus absent, cylindrical to angular ascomata, prominent to sessile, with sloping thalline margin; disc slightly exposed, light brown to pale white, pruinose; margin is distinct, complete, with a thick white margin around the pore and a very fine pilose on the inner surface; thalline margin whole, smooth, and gray-green (Rivas Plata et al. 2012, Caceres et al. 2014). Excipulum entire are apex carbonized, sides and base orange-brown; laterally covered by algal cortical fronds, lacking pericortex; columella absent; hymenium, hyaline, strongly inspersed, inspersion rapidly dissolving in K; epithecium indistinct, hyaline. Paraphyses are unbranched, apically smooth; periphysoids absent; fusiform to clavate asci, 8-spored and ellipsoid ascospores, 3-septate, hyaline, distoseptate with lens-shaped lumina, I+ violet-blue (Caceres et al. 2014). Byssotrema is a monotypic genus in the family Graphidaceae.
Type species: Byssotrema mirabile M. Cáceres, Aptroot & Lücking
Other accepted species: This genus is monotypic.
Figure 1 – Thallus with ascomata of Byssotrema mirabile. Redrawn from Caceres et al. (2014).
References
Entry by
Lu W, Excellence Center of Microbial Diversity and Sustainable Utilization, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, China
(Edited by Saowaluck Tibpromma, Samaneh Chaharmiri-Dokhaharani, & Achala R. Rathnayaka)
Published online 9 December 2024