Myriophyllum Spicatum
Myriophyllum spicatum, commonly known as Eurasian watermilfoil or spiked water-milfoil, is a submerged perennial aquatic plant renowned for its extensive presence in still or slow-moving water bodies. It is part of the Haloragaceae family and is recognized for its potential impact on aquatic ecosystems as an invasive species.
Native to Europe, Asia, and North Africa, Myriophyllum spicatum thrives in a variety of climatic conditions extending across approximately 57 countries from northern Canada to South Africa. This adaptability is key to its invasiveness, allowing it to colonize diverse aquatic environments globally, including regions in North America, Australia, and various parts of Africa.
The plant is characterized by its finely divided, feather-like leaves, which are whorled around the stem. Myriophyllum spicatum produces several chemical compounds such as ellagic acid, gallic acid, pyrogallic acid, and (+)-catechin. These compounds are allelopathic polyphenols, which inhibit the growth of competitive species like the blue-green alga Microcystis aeruginosa.
As an invasive species, Eurasian watermilfoil poses significant challenges to native aquatic ecosystems. It tends to form dense mats that can interfere with the activities such as fishing, swimming, and boating. These dense growths can also displace native aquatic plants, reduce biodiversity, and affect fish habitats. The plant's presence has notably transformed the nearshore ecosystems in places like Lake Tahoe.
Controlling Myriophyllum spicatum requires an integrated management approach. This can include mechanical removal, herbicide application, and biological control methods. Efforts are often made to manage its spread and mitigate its impact on local ecosystems, especially in regions where it is not native.