Dalea purpurea
Purple Prairie Clover
New to me, grown from seeds from Prairie Moon Nursery https://www.prairiemoon.com/dalea-purpurea-purple-prairie-clover-prairie-moon-nursery.html
Reportedly a super food for the endangered Rusty Patched Bumblebee, this native legume is popular with pollinators in general.
Please check out the Prairie Moon listing at the link above for more details.
Photos by Blaine Hansel, USFWS Midwest Region and USFWS Mountain-Prairie via Wikimedia Commons