New North American Records of Anamorphic Powdery Mildew Fungi (Erysiphales) Parasitizing Species of Leucotho? and Limnanthes

摘要

This paper documents the presence of two species of Erysiphales previously unreported in North America. The fungi were encountered on greenhouse-grown host plants in Oregon during the 2006 growing season.? Oidium ericinum? was found on potted plants of? Leucotho? axillaris? (Ericaceae) grown at a wholesale nursery where it resulted in a substantial financial loss to the grower. Oidium limnanthis? was found on potted plants of? Limnanthes? alba? (Limnanthaceae) where it was associated with premature senescence of plants and reduced seed production. This appears to be the first record of a powdery mildew fungus parasitizing a member of the Limnanthaceae in North America. Both species are described and illustrated.