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Common milkweed

Asclepias syriaca

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).



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Healthy Common milkweed Plant
Courtesy, USDA PLANTS Database
Common milkweed
Close-Up of Healthy Common milkweed flowers
Courtesy, USDA PLANTS Database

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Ozone Injury to Common milkweed Leaf
Courtesy, Ozone Biomonitoring Program
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Ozone Injury to Common milkweed Leaf
Courtesy, Ozone Biomonitoring Program
updated on 01/17/2007  I   http://nature.nps.gov/air/Pubs/bioindicators/commonMilkweed.cfm   I  Email: Webmaster