According to Welby Smith’s Trees and Shrubs of Minnesota, these 3 species are difficult to separate and may require more genetic work to determine their relationships.  Reading his key, my one shrub has some characteristics of all 3.

4/30/2021  Leaf blades have few teeth, and the terminal tooth is much longer than the adjacent teeth.  Sepals are about 4mm long.

4/27/2024  Showing the stiff ascending racemes

4/29/2024 The whole plant

4/29/2024  The stems are close together in a group;  there are no other nearby plants.

5/7/2021