Myriophyllum spicatum (Eurasian watermilfoil[3] or spiked water-milfoil) is a submerged perennial aquatic plant which grows in still or slow-moving water.

[5] Myriophyllum spicatum produces ellagic, gallic and pyrogallic acids and (+)-catechin, allelopathic polyphenols inhibiting the growth of blue-green alga Microcystis aeruginosa.

[6] Myriophyllum spicatum is found in disperse regions of North America, Europe, Asia, Australia, and Africa.

Dense Eurasian milfoil growth can also create hypoxic zones by blocking out sun penetration to native aquatic vegetation, preventing them from photosynthesizing.

[4] This hybridization has been observed across the upper midwestern United States (Indiana, Minnesota, Michigan, Wisconsin) and in the Northwest (Idaho, Washington).

Several organizations in the New England states have undertaken large scale, lake-wide hand-harvesting management programs with extremely successful results.

[14] Trailering boats has proven to be a significant vector by which Eurasian milfoil is able to spread and proliferate across otherwise disconnected bodies of water.

[15] In the Okanagan River Basin of south-central British Columbia, a specially-adapted rototiller is used to dredge shallow water to damage or destroy the root system.