A powdery mildew found on plants in the Asteraceae family, including Dandelion (Taraxacum), Mayweeds (Matricaria and Tripleurospermum), Hawks-beard (Crepis), Fleabanes (Erigeron) and Pineappleweed (Matricaria).  Refer to Woods et al (2024) for full host-list.

Golovinomyces cichoracearum and some other species of powdery mildew can affect the same host plants as Podosphaera erigerontis-canadensis - check host-list in Woods et al.(2024). 

host/microscopy

Photograph the mildew on host plant, and add host species to the comments for your record.  Microscopic examination or verification by an expert before submission to NatureSpot may be needed.

Certain plants in the Asteraceae family