Gray Mold Spot

Cristulariella depraedans, commonly known as gray mold spot, sycamore leaf spot or bull's eye spot, is a fungal pathogen that affects maple trees (genus Acer) and certain other woody and herbaceous species. In maples, the foliage becomes affected by small grey lesions which expand and coalesce, the leaves later wilting and falling from the tree early. The disease seems to be associated with cool wet summers, and epidemic years sometimes occur.