How did a native Chicago plant disappear forever?

Sandwiched between a railyard and a Ford assembly plant lie 150 acres of native ecosystem: Indian Ridge Marsh Park. Here in the South Deering neighborhood, birdsong harmonizes with the lowing of a train as we walk into the soggy prairie. The grass is up to our shoulders. The ground is thick with native plants. The mud pulls at our shoes. We’re searching for something smaller than a penny: Thismia americana. “The vegetation looks nice and lush,” says Trevor Edmonson, restoration ecologist with…