Aesculus Leaf Blotch

Guignardia aesculi is a fungus that causes leaf blotch disease on Aesculus sp. in the United States and Europe. The fungus has three distinct morphological stages on the leaf, a sexual (pseudothecial) stage, and two asexual stages; a macroconidial (pycnidial) stage, and a microconidial stage (spermagonial) stage.