Two great local resources:

Indiana Dunes State Park Nature Center at the Indiana Dunes State Park in Chesterton (State Road 49 North til it ends, at the Park, then follow signs to Nature Center -- hours 9:30am-4:30pm, 7 days a week) -- Three brochures: "Native Wildflowers of the Indiana Dunes," "Spring Wildflowers of Indiana," and "Summer and Fall Wildflowers of Indiana"

Wild Ones chapter, Gibson Woods Nature Preserve, Hammond... Local chapter of a national group that promotes the use of native plants in natural landscapes... www.gibsonwoodswild.org (click on "Best Viewed At 1024x768")... National website: www.for-wild.org.  ###