Thorns

The thorns on this bush are bigger and stronger than the branch from which they come. They are clearly meant to protect the bush from large animals, but which animals? One hundred years ago there were almost no deer in Nebraska. But further back there was the American Bison which roamed the central plains for millennia. Even those huge animals would turn away from such thorns to find easier, more tasty morsels nearby.

Homestead National Monument of America, Beatrice, Nebraska