20 September 2007.
Oklahoma, United States
Locality: North side of Highways 412/64/3, 2 miles west of junction with Highway 95, Four Corners.
Coordinates: 36.7622, -101.9489
(Map it)
Elevation: 1097m.
Georeference protocol: Lat/lon determined by GPS
Environment description: Weedy edge of fallowed irrigated circle field to roadside. Associated with grasses and no other Helianthus.
Number of plants sampled: 300
Comment: Population size ~3000; well past flowering.
Collector(s):