Erysiphe adunca is a powdery mildew. The white fibres of the mycelium can sometimes be seen on the surface of living leaves, inhibiting photosynthesis. The spheres can be seen with a hand lens, and may be growing on either surface of the leaves. The coloured spheres (cleistothecia) contain the asci and spores. The colours range from white when very immature through yellow, orange, reddish brown, dark brown and finally black when fully mature.
On the leaves of Salix and Populus.
August to October.
Widespread and fairly frequent in Britain.
Probably fairly frequent, though little recorded in Leicestershire and Rutland.
Leicestershire & Rutland Map
Enter a town or village to see local records
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015