30 September 1997.
South Dakota, United States
Locality: 0.6 mile north of Big Sioux River on Highway 46, north of Hawarden, NE 1/4 of SE 1/4 of Section 10, T95N, R48W, Hawarden North Quad, Union County.
Coordinates: 43.0667, -96.5000
(Map it)
Elevation: 360m.
Georeference protocol: Lat/Lon determined via Map location
Environment description: Disturbed roadside near sand/gravel pit. Full sun on level ground. Well drained area of crushed rock. Associated with Ambrosia artemisiifolia, Euphorbia, Setaria, and Xanthium.
Number of plants sampled: 40
Comment: ~40 heads collected from a population of >100 flowering plants.
Collector(s):