Ronnigeria Petr., Sydowia 1(4–6): 310 (1947).

MycoBank number: MB 4782; Index Fungorum number: IF 4782; Facesoffungi number: FoF 07972; – 1 morphological species (Species Fungorum 2020), molecular data unavailable

Type species: Ronnigeria arctica (Oudem.) Petr., Sydowia 1(4–6): 310 (1947).

Microthyrium arcticum Oudem., Ned. kruidk. Archf, 2 sér. 3: 160 (1886).

Notes: Petrak (1947b) introduced a monotypic genus Ronnigeria to accommodate Ronnigeria arctica (≡ Microthyrium arcticum), epiphytic on Potentilla fragiformis in Novaya Zemlya, Russia (Holm and Holm 1977). The genus is characterized by perithecial, subcuticular, gregarious, amphigenous, orbicular to elliptical ascomata, lacking ostioles, opening by peridial cracks, with a thin-walled peridium, composed of a single layer of dark brown, membranous, pseudoparenchymatous cells and with paraphyses. Asci are 8-spored, clavate, with rounded to truncate bases and ascospores are hyaline, oblong to clavate, or subfusoid (Petrak 1947b; Holm and Holm 1977). The asexual morph of this genus is undetermined. Petrak (1947b) accommo- dated the genus in Leptopeltidaceae and this was followed by various subsequent authors (von Arx and Müller 1975; Holm and Holm 1977; Lumbsch and Huhndorf 2010; Hyde et al. 2013; Wijayawardene et al. 2014a, 2018). The genus has an arctic-alpine distribution and is commonly found on Potentilla spp. in northern Scandinavia and central Europe (Holm and Holm 1977; Farr and Rossman 2020). However, the genus lacks modern taxonomic treatment and molecular data to confirm its phylogenetic affinity. Recollection based on type material is required for a better understanding of this genus.


  • Ronnigeria arctica