Prickly

We were wondering about these -- the spikes on the right --some time back. They are the centers of dried out tuliptree (Liriodendron tulipifera) fruits (center). The samaras, on the left, fall off the flower-like form.
These thorns are, like the tuliptree bits, from the Vale. The largest is over an inch long. I don't know what the bush is, but I wouldn't want to run into it in the dark.