A powdery mildew affecting Nipplewort, Lapsana communis, and Catananche in gardens (ref.: Woods et al, 2024). 

Golovinomyces cichoreraceum s.lat. and Podosphaera eragontis-canadensis may also affect Nipplewort; microscopic examination and reference to Woods et al (2024) is needed to separate them

host/microscopy

• Host Lapsana communis or Catanache
• The conidia have no fibrosin bodies
• Hyphal appressoria lobed
• Germ-tubes are short and lobed.

Photograph the mildew on the host-plant.  Microscopic exmaination and germination of the conidia are required; we recommend that your record is confirmed by an expert before submission to Naturespot. 

usually recorded on Nipplewort, Lapsana communis; roadsides, path edges, gardens, waste ground, etc.