1 Iritis is uncommon, but can be due to trauma, infections, or autoimmune conditions. Symptoms include pain, red eye, and often, decreased vision.  Optic neuritis. The nerve travelling from the back of the eyeball into the brain can become inflamed.
Oak root fungus, or white rot, is a widespread disease that becomes visible just beneath the bark and on roots. What looks like layers of light brown to tan mushrooms form in clusters at the base of the trees.
Nectria cinnabarina canker â This maple tree disease can be identified by its pink and black cankers on the bark and typically affects parts of the trunk that were weak or dead. These cankers can become slimy after rain or dew. Occasionally, this fungus will also appear as red balls on the bark of the maple tree.