This is a common weed of mesic annual cropland. Its most distinctive features include: the small `daisy-like` flower heads with yellow-orange centers and white rays, the finely divided leaves, and the extremely strong and unpleasant odor when the foliage is crushed. In the Pacific Northwest this species is often erroneously referred to as `dog fennel,` a name reserved for Eupatorium capillifolium in the mid-west. In the 2000 edition of Weeds of the West it says `flowers 3/4 inch in diameter.` However, this is actually the measurement of the heads. Similar to Anthemis arvensis and Anthemis austriaca but much more aromatic.