American Sycamore bark - Platanus occidentalis, Leesylvania State Park, Woodbridge, Virginia. According to Wikipedia, "An American sycamore tree can often be easily distinguished from other trees by its mottled exfoliating bark which flakes off in great irregular masses, leaving the surface mottled, and greenish-white, gray and brown."  I find the bark patterns endlessly fascinating.
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/52450054@N04/">Judy Gallagher</a>
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