30 September 1997.
Indiana, United States
Locality: Lawrenceburg on Ohio River banks off Elm Street, Lawrenceburg Township, Lawrenceburg Quad, Dearborn County.
Coordinates: 39.0917, -84.8500
(Map it)
Elevation: 165m.
Environment description: Weedy area on river banks.
Number of plants sampled: 100
Comment: Pop 36. Infestation of thousands.
Collector(s):