The toothache tree is a tree you will want to know about due to its great medical uses. Chewing on its leaves or bark causes a numbness of the mouth, teeth, and tongue which is where it gets it name from. The tree was used for these medical purposes by Native Americans.
Unfortunately the tree is not real common anywhere. And is confined to parts of the Southeast. But if you reside in an area where this tree is found you will certainly want/need to know how to recognize it.
The good news is that even though the tree is not common you aren't likely to simply walk by it without noticing it. This is because the bark of the tree is very unusual. The bark of the tree has what looks like pyramids all over it. Not thin spines like a rose bush or large stickers like devils walking-stick but honest to goodness bumps that look exactly like 1/2 inch tall pyramids. You absolutely can not over look it even if you tried.
The scientific name is Zanthoxylum clava-herculis if you want to look up more about it. Here is a picture of the bark... which is all you need for identification.