Scientific Name: Rhytisma acerinum (Rhytismataceae). The specific name indicates the connection with Maples Acer spp.
English Name: Tar Spot. It is an Ascomycete fungus (a type of sac fungi).
French Name: La Tache goudronneuse (='tar spot'). Also les Croûtes noire de l'Erable (='maple black scabs').
5 Key Characters:
- affects maples and sycamores.
- appears in late summer and autumn.
- first sign is yellow spots on the leaves, which become black.
- black spots can be up to 4 cm across.
- does not kill the tree and there is no resistance to it.
Habitat: Maple and sycamore trees Acer spp.
Fruiting Period: August-September-October-November.
Status: Very common. It is rare to see an unaffected Sycamore Acer pseudoplatanus.
Photographed by Loire Valley Nature: