Note:  Do not rely on this information. It is very old.

Milfoil

Milfoil, i.e. thousand leaves, is the English name of Achillea millefolium, also known as Yarrow, a common British member of the order Composite, so called from its much-cut leaves. It is a herbaceous perennial, with erect stem, about a foot high, bearing a flat group (corymb) of small white or pink flower-heads, each containing very few florets. The whole plant has a pungent smell, and is astringent. The name water-milfoil is applied for the same reason to Mgriophyllum, a genus of aquatic plants, three species of which are British, belonging to the mare's-tail family, Haloragacea;.