The Johnny Appleseed Metro Park District has found a unique way to mark their 50th anniversary and celebrate Arbor Day at the same time.  This year during their annual tree planting for Arbor Day, the park district created an anniversary loop in the Evan's Arboretum at the Ottawa Metro Park.  In the quarter mile loop, there are 50 different species of tree.   The park staff planted the final tree Friday, a Sugar Maple, to complete the loop.  Beside each tree there is a plaque that tells what kind of tree it is, and a QR Code that will link you to the Johnny Appleseed website, which has more information about that type of tree.  Officials hope that people take the time to enjoy the trees and the parks during their anniversary and years to come.