Mayweed Chamomile, Dog Fennel, Stinking Chamomile

Mayweed Chamomile, Dog Fennel, Stinking Chamomile Anthemis cotula is Naturalized in Texas and other States.

I am unsure if this is the plant I have. It looks the same except that mine has dep purple/red flowers with a yellow center. It was grown...Read More from a wildflower seed packet. It has grown like crazy and is very pretty. However the ants seem to love it too! Can anyone tell me if I am correct in my guess of species?

Historical footnote on dog fennel found in an article in Harper's New Monthly Magazine, November 1871 titled "Johnny Appleseed - A Pione...Read Moreer Hero", by W.D. Haley...
"Some of the pioneers were disposed to think that Johnny's humor was the cause of an extensive practical joke; but it is generally conceeded now that a wide spread annoyance was really the result of his belief that the offensively colored weed known in the West as the dog-fennel, but more generally styled, the May-weed, possessed valuable antimalarial virtues. He procured some seeds of the plant in Pennsylvania, and sowed them in the vicinity of every house in the region of his travels. The consequence was that successive flourishing crops of the weed spread over the whole country and caused almost as much trouble as the disease it was intended to ward off; and to this day the dog-fennel, introduced by Johnny Appleseed, is one of the worst grievances of the Ohio farmers."

In Colorado, this plant is considered to be a noxious weed. In many other states, it is considered invasive.