Fungalpedia – Note 2916, Biatoropsis
Biatoropsis Räsänen.
Citation when using this data: Meng QF et al. – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Tremellaceae, Tremellales, Tremellomycetes, Agaricomycotina, Basidiomycota, Fungi.
Biatoropsis was introduced by Raesaenen (1934) to describe B. usnearum, found on Usnea species. It is characterized by hyphae lacking clamps, tremelloid haustoria, and a hymenium with numerous probasidia. The mature basidia are transversely septate, and basidiospores are subglobose to ellipsoid with a lateral apiculus. An asexual stage with catenulate conidia is common, and lunate conidia have been observed (Raesaenen 1934).
Millanes et al. (2016b) introduced two species, Biatoropsis hafellneri on Usnea cornuta and B. protousneae on Protousnea dusenii. Subsequently, Diederich et al. (2020a, 2022d) described six additional species. In total, 11 species are now recognized within Biatoropsis, which was placed in Tremellaceae based on the phylogenetic analysis based on ITS and LSU conducted by Diederich et al. (2022d).
Type species: Biatoropsis usnearum Räsänen.
Other accepted species: Species Fungorum – search Biatoropsis.
Figure 1 – Biatoropsis usnearum redrawn from Diederich et al. (2022d). a Basidiomata on the thallus of Usnea subfloridana. b Basidia. c Haustorial branches. d Catenulate conidia. e Basidiospores. Scale bars: a = 1 mm, b, c = 10 μm, d, e = 5 μm.
References
Raesaenen V. 1934 – Ein paar flechtensystematische Bemerkungen. Annales Botanici Societatis Zoologicae-Botanicae Fennicae “Vanamo” 5 (9), 3–12.
Entry by
Meng QF, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand and School of Public Health, Zunyi Medical University, Guizhou 563000, China.
Published online 7 August 2026