Sclerotinia glacialis F. Graf & T. Schumacher, Mycol Res 99 (1): 113 (1995) [MB # 363084]. Type. SWITZERLAND • Grisons: Radant, 28 July 1991, F. Graf (holotype: Z-ZT 16657). Discussion. Sclerotinia glacialis was isolated and described from glacier buttercups (Ranunculus glacialis) using morphological characters. It was distinguished from the three species accepted by Kohn’s (1979) based on ascospore size (8–10 µm × 22–27 µm in S. glacialis vs. 4–9 µm × 8–20 µm in the other species) and the presence of four-spored asci (vs. eight) (Graf and Schumacher 1995). Although an ITS phylogeny showed S. glacialis clustered with another newly described species, S. nivalis (Senn-Irlet and Peter 2016), the lack of bootstrap support casts doubt on this finding. However, the cells of the ectal excipulum conform to those of Sclerotinia sensu Kohn (1979), supporting S. glacialis as a true Sclerotinia species. Additional phylogenetic work is needed to support its placement in Sclerotinia and to clarify its relationship to other species in the genus.

Published as part of Thomas, Chanel, Wilken, P. Markus, Coetzee, Martin P. A. & Visagie, Cobus M., 2026, Advancing the taxonomy of Sclerotinia (Helotiales, Sclerotiniaceae): a review and recommendations for an important plant-pathogenic genus, pp. e 175737 in IMA Fungus 17 on page e175737, DOI: 10.3897/imafungus.17.175737