Podosphaera clandestina
(Wallr.) Lév.
KW [Darwin] 11787. Place of collection: Russia; Leningrad Oblast; Sankt Peterburg Raion; Petrodvorets (N59°53' E29°54'). Date of collection: 2 June 1926. Associated organism: Crataegus sp. (leaf, shoot). Collector: Grodzinska, V.. Identifier: Heluta, V.P..