The native American D. tricorne Michx. ranges very close to Michigan in the Chicago area, and might be discovered in the southwestern part of the Lower Peninsula, or as an escape from cultivation. It is a fairly low plant (up to ca. 5 dm tall), few-flowered, with follicles spreading when mature. It flowers early in spring, disappearing soon after blooming, unlike most Eaurasian cultivated species.
All species found in Delphinium
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 17, 2019. https://www.michiganflora.net/genus.aspx?id=Delphinium.