Sawadaea bicornis


    This is a powdery mildew that affects the leaves of Field Maple. It becomes more noticeable in Autumn as a whitish covering on the leaves. If conditions are favourable it produces fruiting spores which can be seen through a lens as tiny yellow spheres amongst the powdered surface.

    Similar Species

    There are two almost identical species that can only separated by microscopic examination of the attachments on the chasmothecia.

    Identification difficulty
    Recording advice

    A photo is needed showing both the mildew and the leaf so that it is recognisable as Field Maple.


    on the leaves of Field Maple.

    When to see it

    Mainly Autumn.

    UK Status


    VC55 Status


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    Leicestershire & Rutland Map

    MAP KEY:

    Yellow squares = NBN records (all known data)
    Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

    UK Map