Rhytisma acerinum

Tar Spot

Rhytisma acerinum, Tar Spot, is a pathogenic fungus that grows within the leaves of Sycamore, Acer pseudoplatanus. It is so common that it would be rare to find an uninfected Sycamore. Rhytisma acerinum does not appear to cause any harm to the tree, other than the appearance.


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Rhytisma acerinum, Tar Spot
Tar Spot
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Rhytisma acerinum, Tar Spot
Tar Spot
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Rhytisma acerinum, Tar Spot
Rhytisma acerinum
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Rhytisma acerinum leaf section
Leaf section

Photograph detail


Slide 1: Rhytisma acerinum, Tar Spot, on Sycamore, Acer pseudoplatanus. Railway, Redmire. October.


Slide 2: Rhytisma acerinum, Tar Spot, on Sycamore, Acer pseudoplatanus. Redmire. October.


Slide 3: Rhytisma acerinum, Tar Spot, on Sycamore, Acer pseudoplatanus. Redmire. October.


Slide 4: Rhytisma acerinum, Tar Spot, on Sycamore, Acer pseudoplatanus. Section through infected part of leaf. Upper surface to the right. Redmire. October.