(Named after Achilles, who is said to have discovered its healing qualities). Family, Composite. Color, white, sometimes with a pink tinge. Leaves, twice pinnately divided into sections which are 3 to 5-cleft. Rays of flower, 5 to 10. The small flowers grow in flat, stiff, hard corymbs, 3 or 4 inches across. The stems are simple, stout, covered with the dissected, tansylike leaves. Not unpleasantly scented. August.

A discouraging weed, which, once introduced into a lawn, is almost impossible to eradicate. Yarrow tea has had a reputation in many countries among some people for medicinal virtues.