Tanacetum vulgare
(Common Tansy or Beggar's Buttons)

Family: Asteraceae (Sunflower)
Noxious Weed!
  
Common Tansy is easily identified by its clusters of yellow, button-like flower heads. Leaves are pinnately divided with toothed leaflets. Plants grow to about two feet tall. An escaped ornamental that can invade natural areas, Common Tansy is a noxious weed that should be controlled aggressively before it becomes established.

Vegetation zone:  Plains, Foothills, Montane
Time of bloom:  July - October
Origin:  Introduced  Noxious Weed
Eastern Colorado Wildflowers