This one took me aback. Baptisia bracteata and B. alba are known from the prairie, but B. australis is not. Nor is it in the Arboretum database other than some garden plantings on the east side (a mile or more away). It has long been known from West Chicago Prairie (also in DuPage County), where it is theorized to have come in on the long-abandoned railroad. Ray Schulenberg knew that site but first saw it in 1975, years after his prairie was established. A mystery.