University of Colorado Museum of Natural History Herbarium Vascular Plant Collection (COLO:V)
Cirsium undulatum (Nuttall) Sprengel
23 June 2020
United States, Colorado, Jefferson, Ranson/Edwards Homestead Open Space Park. High plains above Rocky Flats, 1.7 mi west on CO Hwy 72 from CO Hwy 93, 1.2 mi generally north on Plainview Road, then 450 m east along the north side of an ephemeral stream, 19.9 km NNW of the GNIS location of Golden.