Eurasian Watermilfoil

Myriophyllum spicatum

Description


Non-Native

Eurasian watermilfoil is a perennial plant native to Europe, Asia, and Africa and was probably brought to the U.S. as an aquarium plant. Today it is considered one of the most aggressive and problematic plants in the U.S. because of the dense colonies which it forms. The stems are multi-branched, somewhat reddish in color, with gray-greenish feather-like leaves. The leaves are in whorls of 3 to 5 around the stem with each leaf divided into 12 or more pairs of thin thread-like leaflets. Reddish flowers are borne on leafless spikes that rise above the surface a few inches. Eurasian watermilfoil can spread from seeds or by fragmentation.

Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates. Eurasian watermilfoil seeds are consumed by ducks, while muskrats and nutria will consume the stems. Eurasian watermilfoil is a non-native and should not be spread.

This plant is not native to North America and it is illegal to possess or transport this species in Texas. Please report any sightings of this plant to Texas Park and Wildlife Department.