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Eurasian water-milfoil

Eurasian water-milfoil
(Myriophyllum spicatum)

Description:  Branching stems of Eurasian water-milfoil emerge from thick, spreading roots. Eurasian water-milfoil does not form winter buds.

Habitat:  Eurasian water-milfoil is an extremely well adapted plant, able to thrive in a wide variety of environmental conditions. It grows well in still and flowing waters, endures mild salinities and can survive under ice. Eurasian water-milfoil grows rooted in water depths from 1 to 10 meters, generally reaching the surface in depths of 3 to 5 meters. Though adapted to a wide variety of substrate types, this species seems to favor fine-textured, inorganic (lifeless) sediments.

Annual Cycle:  Eurasian water-milfoil is an extremely hardy aquatic perennial that grows through root division, broken pieces, and seeds. Flowering spikes typically rises from the water in mid to late summer, but not all colonies produce flowers. Splintering may occur during the growing season with stem sections developing roots even before they separate from the parent plant. Toward the end of the growing season some plants break apart and die back to their rootstalks; others overwinter intact. New growth sprouts from roots and overwintering plants and plant pieces as the water begins to warm in the spring, growing rapidly toward the surface. Certain milfoils are able to sneak in with other, closely related, milfoil species. Eurasian water-milfoil is known to sneak in with Maine’s native northern water-milfoil.

Origin and U.S. Range:  Eurasian water-milfoil is native to Europe and Asia. It was introduced to North America in the 1940s. Spreading rapidly since its introduction, Eurasian water-milfoil is now present in most states, including in the Scarborough quarry pond of Maine. It also occurs in most Canadian provinces including Quebec.

Look a likes:  May be confused with bladderworts, hornworts, mermaid weeds, water crowfoots, and other leafy water-milfoils.

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