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.
A. From your description and photos, the problem is lichens growing on the bark of your trees. Lichens are a fungus living in a symbiotic (mutually beneficial) relationship with blue-green bacteria. The fungus surrounds the bacteria. They often grow on tree trunks, unfinished wooden fences, and even rocks.Lichens growing on a tree trunk. Lichens pose no threat to your trees' health, or to you and your family. Their presence is actually a sign that the air in your neighborhood is relatively clean-they do not grow in areas where the air polluted.hey often grow on tree trunks, unfinished wooden fences, and even rocks. Lichens growing on a tree trunk. Lichens pose no threat to your trees' health, or to you and your family. Their presence is actually a sign that the air in your neighborhood is relatively clean-they do not grow in areas where the air polluted.