Andrej Kunca, National Forest Centre - Slovakia, Bugwood.org

stromata

Frantisek Soukup, Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on maple (Acer spp.)

Frantisek Soukup, Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on maple (Acer spp.)

Gil Wojciech, Polish Forest Research Institute, Bugwood.org

Poland

Gil Wojciech, Polish Forest Research Institute, Bugwood.org

Poland

Andrej Kunca, National Forest Centre - Slovakia, Bugwood.org

tar spot of maple (Rhytisma acerinum) sign on maple (Acer spp.)

Clemson University - USDA Cooperative Extension Slide Series , Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on maple (Acer spp.)

Haruta Ovidiu, University of Oradea, Bugwood.org

Salaj County, Central Romania (1 september, 2005)

USDA Forest Service - Northern and Intermountain Region , USDA Forest Service, Bugwood.org

early stage on maple leaves

Minnesota Department of Natural Resources - FIA , Minnesota Department of Natural Resources, Bugwood.org

early stage on leaves

Florida Division of Plant Industry , Florida Department of Agriculture and Consumer Services, Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on red maple (Acer rubrum)

Florida Division of Plant Industry , Florida Department of Agriculture and Consumer Services, Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on maple (Acer spp.)

Florida Division of Plant Industry , Florida Department of Agriculture and Consumer Services, Bugwood.org

tar spot of maple (Rhytisma acerinum) symptoms on maple (Acer spp.)

Andrej Kunca, National Forest Centre - Slovakia, Bugwood.org

stromata

Dawn Dailey O'Brien, Cornell University, Bugwood.org

Black tar-like fruiting structures on the upper side of leaves are diagnostic signs of giant tar spot.

Bruce Watt, University of Maine, Bugwood.org

Apothecia in tar spots (Spring)