27 September 1996.
Illinois, United States
Locality: On east bank of Illinois River 1 mile south of Beardstown Bridge, Section 21, Beardstown Township, T18N, R12W, Beardstown Quad, Cass County.
Coordinates: 40.9917, -90.5000
(Map it)
Elevation: 139m.
Environment description: Construction site.
Number of plants sampled: 30
Comment: Pop 22.
Collector(s):