Hi Matt,
Try searching with the spelling Mimosa. On a previous page on tree and plant ID here we had the smallest member of that family I had seen, sensitive mimosa. Down at the Clemson (SC) botanical gardens a month ago there were some small ground cover plants that were not sensitive but had to be members of the family also, had just never looked down for em. Its in the legume family. We have your tree in southwestern VA. Mimosa is the only common name I've heard for the tree.