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Eurasian Watermilfoil

Eurasian watermilfoil. Photo by Alison Fox, University of Florida, Bugwood.org

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Common Name: Eurasian watermilfoil
Scientific Name: Myriophyllum spicatum
Origin: Europe and Asia

Description

Eurasian watermilfoil is a submerged perennial that looks like many native aquatic plants, including native milfoil species. Eurasian watermilfoil usually has four feathery leaves whorled around the stem. Each leaf is finely divided, has more than 9 leaflets, and a flat leaf tip. The plant can reach lengths of 20 ft. and branches near the water’s surface. Tiny pink flowers may occur on an emergent spike late in the summer.

Habitat

This plant grows in a variety of depths, sediment types and flowing conditions.

Threat

Plant fragments, which break off easily, can be transported from lake to lake on boat trailers or fishing gear. These fragments can start new populations, which form dense mats that degrade habitat and reduce recreational access.

Management

Once watermilfoil becomes well-established within a waterway, it is very difficult to remove. A variety of control methods used nationwide to manage watermilfoil infestations include physical, mechanical, biological and chemical techniques. Prevention is the most effective control.

Regional Distribution

Widespread

WNY PRISM Priority

Tier 4 – Local Control

Invasive Species Priorities – Tier Chart

Eurasian watermilfoil is a prohibited species in New York State – for more information on Prohibited and Regulated Species, visit http://www.dec.ny.gov/animals/99141.html.

Native Alternatives

Northern watermilfoil (Myriophyllum sibiricum)

Coontail (Ceratophyllum demersum)

Slender/bushy naiad (Najas flexilis)