"Common yarrow or milfoil is a plant that’s familiar to hikers as well as gardeners. A member of the aster or composite family (Asteraceae), yarrow has flat-topped or dome-shaped clusters of small white flowers that bloom from April to October. An attractive, hardy perennial, yarrow can reach about 3 feet in height. Its aromatic, fine, feathery-cut leaves give the plant a soft, fern-like appearance.
Numerous tribes in North America used yarrow for a variety of ailments. The crushed plant was applied to wounds and burns. The dried leaves were used as a tea to soothe colds, fever, and headache. Yarrow beer has been brewed in Europe since the middle ages. The Chinese considered yarrow plants to be good luck. Even Lewis and Clark were acquainted with yarrow. It was collected during the Lewis and Clark Expedition while they were camped near Kamiah, Idaho in May 1806. "