Common yarrow is a very common, perennial, herb 30-100 cm tall. Its alternate leaves are finely and pinnately dissected to appear almost feather-like. Common yarrow has flat- or round-topped clusters of heads (4-6 mm dia), each with about 5 white-petaled ray flowers and 10-30 cream-colored disk flowers. The fruits are flattened achenes without a pappus. Common yarrow grows in dry to moist open sites such as fields, meadows, roadsides, and clearings at low to high elevations.