United States, Illinois, DuPage, Morton Arboretum, In the city of Darien, southeast of the intersection of 75th Street and Lyman Avenue, along a roadway that enters the Darien Town Centre from Lyman Avenue.
Some of this area is remnant and other sections have been planted. The area where the plants were found was planted more than 10 years ago and has not had any management. The plants have persisted and had weedy associates. Observed in bloom on July 31, 2012.