Podosphaera aphanis infects leaves, flowers, and fruit of plants in the Rosaceae family, including Lady's Mantle (Alchemilla), Parslet Piert (Aphanes arvensis), Strawberry (Fragaria), Herb Bennet or Avens (Geum), Cinquefoils/Tormentil etc. (Potentilla) and Blackberry/Raspberry etc. (Rubus).  It has also been recorded on Eucalyptus. 

Other powdery mildews may be found on Eucalyptus.   Check host list in Woods et al (2024) - other plants in the Rosaceae family may be affected by different species of powdery mildew

host (Rosaceae) Eucalyptus

Photograph the mildew on host plant, and add host species to the comments for your record. If you are recording on Eucalyptus, microscopic examination or verification by an expert before submission to NatureSpot will be needed

certain plants in the Rosaceae family; Eucalyptus