BugwoodWiki Article

Eurasian water-milfoil
Myriophyllum spicatum L.

Overview

Appearance
Myriophyllum spicatum is a submersed aquatic plant that invades lakes, ponds, and other aquatic environments throughout the United States. The plants are rooted and the stems grow up to the water surface, usually reaching 3-10 ft. (0.9-3 m) in length and can be as much as 30 ft. (9.1 m) long.
Foliage
Leaves are bright green, finely dissected, and whorled. The delicate leaflets give this plant a feathery appearance.
Flowers
Myriophyllum spicatum has both male and female flowers on the same inflorescence. The female flowers are basal while the male flowers are located distally. The female flowers have a 4-lobed pistil and lack sepals and petals. The male flowers have 4 pink petals and 8 stamens.
Fruit
The very small globular fruit of Myriophyllum spicatum are indehiscent, and contain 4 seeds.
Ecological Threat
Myriophyllum spicatum requires stagnant to slowly moving water and can tolerate brackish conditions. It forms dense mats of leaves restricting light availability, leading to a decline in the diversity and abundance of native macrophytes. In addition, Myriophyllum spicatum displaces the native species of watermilfoil and reduces habitats for fish spawning and feeding. It is native to Europe, Asia, and northern Africa.

Resources

Selected Images


5273023
5273023

Eurasian water-milfoil
Myriophyllum spicatum
Infestation
Leslie J. Mehrhoff
1624031
1624031

Eurasian water-milfoil
Myriophyllum spicatum
Plant(s)
Alison Fox
5273022
5273022

Eurasian water-milfoil
Myriophyllum spicatum
Flower(s)
Leslie J. Mehrhoff
5400612
5400612

Eurasian water-milfoil
Myriophyllum spicatum
Foliage
Graves Lovell
5400618
5400618

Eurasian water-milfoil
Myriophyllum spicatum
Foliage
Graves Lovell
5400619
5400619

Eurasian water-milfoil
Myriophyllum spicatum
Plant(s)
Graves Lovell
5447202
5447202

Eurasian water-milfoil
Myriophyllum spicatum
Plant(s)
Leslie J. Mehrhoff
0002001
0002001

Eurasian water-milfoil
Myriophyllum spicatum
Plant(s)
Robert L. Johnson
5308029
5308029

Eurasian water-milfoil
Myriophyllum spicatum
Seed(s)
Steve Hurst
5308027
5308027

Eurasian water-milfoil
Myriophyllum spicatum
Plant(s)
USDA PLANTS Database

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Invasive Listing Sources

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Rosidae
Order: Haloragales
Family: Haloragaceae
Genus: Myriophyllum

Other System Links

Plants: MYSP2
Bayer: MYPSP
GRIN: 400094
ITIS: 27039
NPDN Pest: PCDABBD
NPDN Host: 36432

Synonyms and Other Names

Other Common Names:
spiked watermilfoil

Categories

Category: Aquatic
Category: Forbs/Herbs