Colorado
Flora of North America recognizes twenty-one varieties of E. nauseosa, all native to the western U.S. Eight are native to Colorado. Varieties nauseosa, oreophila and gravolens can be found throughout the State and are native to the Fort Collins area. Varieties speciosa, juncea and leiosperma are found on the west slope of Colorado. Varieties bigelovii and ammophila are primarily found in the San Luis Valley.