Erysiphe digitata

The fungus forms whitish robust patches on the undersides of leaves of mainly evergreen rhododendrons. Erysiphe digitata, like most Erysiphaceae, is highly host-specific and infects only the genus Rhododendron.^[2]

The fungus was formally described in 2000 by A.J. Inman and U. Braun. The type specimen was collected in Belgium, on Rhododendron mekongense var. melinanthum, with the basionym Microsphaera digitata.^[2] The species was transferred to the genus Erysiphe by the same authors later the same year.^[3] Tymon et al. (2022) provided an ex-holotype sequence of this species, clarified the phylogenetic affinity, and demonstrated that this species with Asian origin has been introduced in the United States on evergreen Rhododendron spp.^[4]