Solanum elaeagnifolium (Silverleaf Horsenettle)
Solanaceae (Nightshade)
A potentially troublesome weed usually found only in the southernmost regions of Colorado, S. elaeagnifolium was recently found in Fort Collins. Those plants may have been introduced as a contaminant in a revegetation seed mix.

Vegetation zone:  Plains
Time of bloom:  July - September
Origin:  Native to southwest U.S.,  Introduced in northern locations
Eastern Colorado Wildflowers