|Rapid Color Guide: Plants|
And lastly, if you're in the Chicago area and would like to explore outdoors, you can check out the Field Museum's Keys to Nature Project (http://fm1.fieldmuseum.org/keystonature/). This online resource guides explorers through a series of questions to identify plants and animals in the Chicago area. Looking it over, I think the resource would also work for a larger region around Chicagoland. If you're in the Midwest, check it out and see if it works for you too.