Found throughout the United States, except on the Florida peninsula. Fibrous roots with an accompanying rhizome system. Seedlings develop into a rosette and have hairs that mostly lay flat against the leaf surface . Young plants are almost fern-like. Lower basal leaves have petioles.
Upper leaves are alternate and without petioles, often smaller than the lower leaves.
All leaves are finely dissected, 1-6 inches long, up to 1 inch wide, with many short inconspicuous hairs. Many white or sometimes pinkish flowers form a single, flat-topped rounded cluster of flowers that are often confused as a single flower. Many of these flat-topped clusters of flowers occur on a single plant at the ends of branches. Individual flowers are 3-5 mm in diameter. However, the leaves of mayweed chamomile are much less hairy than those of common yarrow.