Leaves are twice as long as wide. This should indicate it's American and not Oriental bittersweet.
Berry is growing in high bunches on the outer branches of the tree. Numerous berries dropped around the tree confirm they are from this specimen. Could be a vine growing on and up the branches?
not the best pictures, I know
BIO 323 Veg Survey This moss was dried out so it was more difficult to see, but the structure was soft and spongey, and loosely structured. it was growing on a rock