[Chamomiles: The Genus Anthemis in the Columbia River Gorge of Oregon and Washington]
The photo above shows a close-up of the flower head of mayweed chamomile. Photographed on the trail along the westbank of Catherine Creek in the central Columbia River Gorge........July 7, 2006.
Mayweed chamomile is a bushy, branched annual with a foul smell. As a plant, it is fairly attractive, but it spreads readily to become a pesky weed. Plants range from 10-60 cm tall The twice to three-times pinnatifid leaves are 2-6 cm in length, with very narrow leaflets.
The flower heads are numerous, being found at the ends of the branches as well as in the leaf axils. The yellow disks are mostly 5-10 mm wide, surrounded by 10-20 white rays which range from 5-11 mm long. The involucre is sparsely hairy.
Mayweed chamomile is found in heavily disturbed places, such as roadsides, fields, and waste areas.
A native of Europe, Mayweed chamomile is now found widespread throughout North America. It is found throughout the Columbia River Gorge in disturbed places between the elevations of 0'-2000'.
Contact with mayweed may cause skin rashes, blistering of livestock noses and mouths, and an irritation to the mucous membranes of grazing livestock. It has also been known to give a strong flavor to the milk of dairy cattle and goats.