They were all gone now and he was alone with his back against a tree.

It'd have been better if I'd told him to go ahead up against the tree.

He gave up after some minutes and placed his back against a tree.

The youth stood with his back against a great tree.

Steve tried to step back out of range and found himself up against a tree.

He sat back against a tree, reached for the wine again.

I sat on solid ground, my back against a tree.

He sat back against the tree that had been his protection earlier.

Others leaned against trees or sat on the ground, watching.

I hit my head against a tree and was stunned.