Gray treefrog complex

These two species are virtually indistinguishable in appearance. These treefrogs can be light gray to green, although they are usually gray, and have warty-looking skin with irregularly shaped dark markings on the back. The undersides of the thigh are bright orange to yellow and mottled with dark markings. They have enlarged toe pads and a white spot beneath each eye. Cope's gray treefrog is generally the smaller of the two species, usually with a light gray back that can turn completely green. It has less dark mottling on the underside of the thighs than the gray treefrog. The adult gray treefrog is slightly larger than an adult Cope's gray treefrog and varies from gray to mostly green. The author has noticed that the gray treefrog cannot become completely green on the back. It will always have black and/or gray lines showing. (information from "A Field Guide to Oklahoma's Amphibians and Reptiles")