Milfoil

Milfoil is a common name for several plants and may refer to:
 * The flowering terrestrial plant Achillea millefolium (known commonly as yarrow)
 * Various species of the genus Achillea (yarrows or milfoils)
 * The aquatic plants in the genus Myriophyllum (commonly referred to as water milfoil and other variations including the word milfoil)