Solanum triflorum (Cutleaf Nightshade)
Family: Solanaceae (Nightshade)
  
Cutleaf Nightshade has white flowers with yellow anthers. Leaves are deeply lobed and shaped like oak leaves. It is an introduced weed that grows on dry or moist sites.

Vegetation zone:  Plains, Foothills
Time of bloom:  July - September
Origin:  Introduced
Eastern Colorado Wildflowers