Erysiphe polygoni
DC.
KW [Darwin] 12243. Place of collection: Ukraine; Sumy Oblast; Lebedyn District; Mykhailivska Tsilyna reserve; small lake, near (N50°45' E34°10'). Date of collection: 7 September 1954. Associated organism: Polygonum lapathifolium (leaf). Collector: Morochkovsky, S.F.. Identifier: Heluta, V.P..