Big-leaf aster

Ozone injury usually appears as black or purple spots (stipple), yellow or white bleached spots (chlorotic mottle, needle tip burn), or leaf browning (necrosis). Ozone may also cause premature leaf drop (senescence).

Healthy Big-leaf aster Plant Courtesy, USDA Ozone Biomonitoring Program Ozone Injury to Big-leaf aster Courtesy, Wisconsin State Herbarium Ozone Injury to Big-leaf aster Courtesy, www.borealforest.org

Ozone Injury to Big-leaf aster Leaf Courtesy, USDA Ozone Biomonitoring Program

Ozone Injury to Big-leaf aster Leaf Courtesy, USDA Ozone Biomonitoring Program

Ozone Injury to Big-leaf aster Leaf Courtesy, USDA Ozone Biomonitoring Program