Anthracnose is a common fungal disease that affects many varieties in Kansas each year.  Some affected trees are:  Maple, Ash, Sycamore, Elm, Oak, Walnut and Cottonwood. Many of these diseases develop in the spring and have similar leaf symptoms (blotchy leaf spots), but the common thread to all anthracnose diseases is the fact that the fungi which cause them produce similar, cup-like fruiting structures (spore-producing structures) called acervuli. These fungi also are host specific. For example, the fungus which causes anthracnose on maple will not cause injury to black walnut, and vice-versa. Anthracnose can be treated effectively if caught by fungicide.