It has fine, purple flowers in the spring. I want to buy the tree locally. All of these trees bloom in shades of purple but the tamarix doesn't bloom in spring with the others. Look at the bark and the leaves to see if you have one of the locusts or a redbud, rather than a tamarix. Locusts and redbud have dark gray to black bark.
Tamarix bark is light gray.
Locusts have small, oval leaflets arranged 10 or 11 together, like a fern. Redbud has large leaves shaped like plump hearts. Redbud is sold at most local garden centers, and tamarix may be available there as well. Arrowhead Alpines in Fowlerville offers redbud, tamarix and Robinia via on-site or mail order sales. The trunk is in the neighbor's yard but its messy top is entirely in mine.