The flat-topped, white flower clusters of yarrow are sometimes confused with wild carrot, however, the flowers have a much rougher texture and the leaves are entirely different.  The leaves are singular, fern-like and highly dissected, soft to the touch, and aromatic.  Occasionally, the flowers may contain a tinge of pink, this form is often planted in the gardens.  Yarrow is now a widespread alien across the US, found not only along roadsides and field edges but also in the open woods.