Myriophyllum spicatum
Encyclopedia
Myriophyllum spicatum is a species of Myriophyllum
native to Europe
, Asia
, and north Africa
. It is a submerged aquatic plant, and grows in still or slow-moving water.
(usually between 15-35 mm long)are borne in whorls of four, pinnate, with the numerous leaflets thread-like, 4–13 mm long. Plants are monoecious with flower
s produced in the leaf axils (male above, female below) on a spike 5–15 cm long held vertically above the water surface, each flower inconspicuous, orange-red, 4–6 mm long. Eurasian water milfoil has 12- 21 pairs of leaflets while northern watermilfoil M. sibiricum only has 5-9 pairs. The two can hybridize and the resulting hybrid plants can cause taxonomic confusion as leaf characters are intermediate and can overlap with parent species.
in the 1940s where it has become an invasive species
in some areas. As of 2003 Eurasia
n watermilfoil was found in every state of the contiguous US save for Wyoming and Montana, with Rhode Island, New York, New Jersey, Michigan, Minnesota, and Washington state having the largest areas of infestation.
, the water veneer moth, feeds upon and damages this water milfoil. It has been used as an agent of biological pest control
against the plant in North America. The milfoil weevil (Euhrychiopsis lecontei
) has also been used as biocontrol. Another method for biocontrol is Grass Carp
, (one of the Asian Carp
species) which have been bred as sterility
, is sometimes released into affected areas, since these fish primarily feed on aquatic plants and have proven effective at controlling the spread. However, the carp prefer many native species to the milfoil and will usually decimate preferred species before eating the milfoil.
Since roughly 2000, hand-harvesting of invasive milfoils has shown much success as a management technique. Several organizations in the New England states have undertaken large scale, lake-wide hand-harvesting management programs with extremely successful results. Acknowledgment had to be made that it is impossible to completely eradicate the species once it is established. As a result, maintenance must be done once an infestation has been reduced to afford-ably controlled levels. Well trained divers with proper techniques have been able to effectively control and then maintain many lakes, especially in the Adirondack Park in Northern New York where chemicals, mechanical harvesters, and other disruptive and largely unsuccessful management techniques are banned. The Adirondack Watershed Institute (AWI) of Paul Smiths College is one organization whose research has shown time and again the effectiveness of hand-harvesting techniques. Two past employees of the Institute formed a private company called Aquatic Invasive Management, LLC (AIM)) which has taken the productivity of past hand-harvesting techniques to new heights with private innovation. It is becoming apparent that hand-harvesting is minimally disruptive to the ecology, highly effective per dollar spent, economically beneficial in the form of good paying job creation and universally applicable.
Myriophyllum
Myriophyllum is a genus of about 69 species of freshwater aquatic plants, with a cosmopolitan distribution. The center of diversity for Myriophyllum is Australia with 43 recognized species...
native to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, and north Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. It is a submerged aquatic plant, and grows in still or slow-moving water.
Description
Eurasian watermilfoil has slender stems up to 3 m long. The submerged leavesLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
(usually between 15-35 mm long)are borne in whorls of four, pinnate, with the numerous leaflets thread-like, 4–13 mm long. Plants are monoecious with flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s produced in the leaf axils (male above, female below) on a spike 5–15 cm long held vertically above the water surface, each flower inconspicuous, orange-red, 4–6 mm long. Eurasian water milfoil has 12- 21 pairs of leaflets while northern watermilfoil M. sibiricum only has 5-9 pairs. The two can hybridize and the resulting hybrid plants can cause taxonomic confusion as leaf characters are intermediate and can overlap with parent species.
Introduced areas
Myriophyllum spicatum was likely first introduced to North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in the 1940s where it has become an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in some areas. As of 2003 Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
n watermilfoil was found in every state of the contiguous US save for Wyoming and Montana, with Rhode Island, New York, New Jersey, Michigan, Minnesota, and Washington state having the largest areas of infestation.
Impact
In lakes or other aquatic areas where native aquatic plants are not well established, the Eurasian plant can quickly spread. It has been known to crowd out native plants and create dense mats that interfere with recreational activity. Eurasian watermilfoil can grow from broken off stems which increases the rate in which the plant can spread and grow. In some areas, the Eurasian Watermilfoil is an Aquatic Nuisance Species. Eurasian watermilfoil is known to hybridize with the native northern watermilfoil (M. sibiricum)and the hybrid taxon has also becomes invasive in North America. It is known from across the USA upper midwest (Minnesota, Michigan, Wisconsin) and in the Northwest (Idaho, Washington).Control
The aquatic moth Acentria ephemerellaAcentria ephemerella
Acentria ephemerella is a species of grass moth known as the watermilfoil moth or water veneer. It is used as an agent of biological pest control against the noxious aquatic plant known as Eurasian watermilfoil .The adult male is a white moth with a wingspan of about 12 millimeters. There are two...
, the water veneer moth, feeds upon and damages this water milfoil. It has been used as an agent of biological pest control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
against the plant in North America. The milfoil weevil (Euhrychiopsis lecontei
Euhrychiopsis lecontei
Euhrychiopsis lecontei is a type of weevil that has been investigated as a potential biocontrol agent for Eurasian water milfoil . It is found in the eastern and central United States and western Canada .-Life cycle:...
) has also been used as biocontrol. Another method for biocontrol is Grass Carp
Grass carp
The grass carp is a herbivorous, freshwater fish species of family Cyprinidae, and the only species of the genus Ctenopharyngodon. It is cultivated in China for food, but was introduced in Europe and the United States for aquatic weed control...
, (one of the Asian Carp
Asian carp
Many species of heavy-bodied cyprinid fish are collectively known in the United States as Asian carp. Cyprinids from the subcontinent [for example, catla and mrigal ] are not included in this classification, and are known collectively as "Indian carp".Eight Asian carp have been substantially...
species) which have been bred as sterility
Sterility
Sterile or sterility may refer to:*Sterilization , a term referring to any process that eliminates or kills all forms of life from an item or field*Sterility , an inability of a living organism to effect sexual reproduction...
, is sometimes released into affected areas, since these fish primarily feed on aquatic plants and have proven effective at controlling the spread. However, the carp prefer many native species to the milfoil and will usually decimate preferred species before eating the milfoil.
Since roughly 2000, hand-harvesting of invasive milfoils has shown much success as a management technique. Several organizations in the New England states have undertaken large scale, lake-wide hand-harvesting management programs with extremely successful results. Acknowledgment had to be made that it is impossible to completely eradicate the species once it is established. As a result, maintenance must be done once an infestation has been reduced to afford-ably controlled levels. Well trained divers with proper techniques have been able to effectively control and then maintain many lakes, especially in the Adirondack Park in Northern New York where chemicals, mechanical harvesters, and other disruptive and largely unsuccessful management techniques are banned. The Adirondack Watershed Institute (AWI) of Paul Smiths College is one organization whose research has shown time and again the effectiveness of hand-harvesting techniques. Two past employees of the Institute formed a private company called Aquatic Invasive Management, LLC (AIM)) which has taken the productivity of past hand-harvesting techniques to new heights with private innovation. It is becoming apparent that hand-harvesting is minimally disruptive to the ecology, highly effective per dollar spent, economically beneficial in the form of good paying job creation and universally applicable.
External links
- Species Profile- Eurasian Watermilfoil (Myriophyllum spicatum L.), National Invasive Species Information Center, United States National Agricultural LibraryUnited States National Agricultural LibraryThe United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
. Lists general information and resources for Eurasian Watermilfoil. - Flora Europaea: Myriophyllum spicatum
- Flora of Taiwan: Myriophyllum spicatum
- http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=eng&journal=cjfas&volume=63&year=2006&issue=5&msno=f06-010
- Invading Species.com Ontario Ministry of Natural Resources and the Ontario Federation of Anglers and Hunters
- Jepson Manual Treatment
- USDA Plants Profile
- USDA ARS. Foiling Watermilfoil
- Photo gallery