Many of the State Parks have good trails and nice wildflower displays. Muskegon's JP Hoffmaster State Park is probably the best known with its annual Trillium Festival. Warren Woods State Park is closer and should be good for wildflowers. Warren Dunes State Park has some nice wooded trails with wildflowers. (Most of its visitors stick to the beaches and dunes, but the forested areas are nice too.)
There's a nice webpage, Michigan Wildflowers, that has photos of many wildflowers blooming in Michigan
I teach economics at Kalamazoo College. My wife is also an economist. We were on sabbatical in Europe for the 2014-15 academic year. (Salamanca, Spain, followed by Oxford, UK.) We were in Uruguay for the 2006-7 academic year.