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Myriophyllum Spicatum Myriophyllum spicatum Eurasian Watermilfoil A Non-Native Submerged Aquatic Plant EURASIAN WATERMILFORD (EWM) & STARRY STONEWORT (SSW) SUBMERGED AQUATIC PLANTS IN LAKE WAWASEE & SYRACUSE LAKE PROBLEM STATEMENT1 EWM is present throughout the littoral zone in both Lake Wawasee & Syracuse Lake. EWM & SSW are impacting the use of Lake Wawasee & Syracuse Lake in many areas. Both EWM & SSW form dense mats in many areas, which can inhibit fishing, swimming, and boating. Observations from Lake Wawasee & Syracuse Lake over the past 8 years indicate that SSW is extremely aggressive & even appears to be out-competing EWM in many areas. These invasive plant beds may also prevent the growth of beneficial native species which often provide less recreational interference & better quality fish habitat. SSW is currently present In over 239 surface acres on Lake Wawasee and over 231 acres in Syracuse Lake. 1Source: Aquatic Weed Control. 2018. Lake Wawasee and Syracuse Lake Aquatic Vegetation Management Plan, 2017 Update. Kosciusko County, Indiana. 55pp. [see page 5] EURASIAN WATERMILFOIL Myriophyllum spicatum General Characteristics 1. Eurasian watermilfoil (EWM), Myriophyllum spicatum, is a submerged perennial vascular plant in the family Haloragaceae. a. It is native to Europe, Asia, & northern Africa (Patten 1954). It also occurs in India, Canada, & the U. S. 2. EWM leaves, about 2 inches long, are olive-green, arranged in whorls of 3 to 6 (usually 4) leaves around the stem. Leaves are deeply dissected with 14 or more uniform (in diameter) leaflets on Source: Online photo. Q.bank- each leaf, giving the leaves a feathery 250 X250. EWM leaves & leaflets. appearance (Patten 1954). EURASIAN WATERMILFOIL Myriophyllum spicatum General Characteristics 3. M. spicatum flowers twice as year, typically mid-June & late July, followed by autofragmentation of the plant after each flowering (Nichols 1975). Flowers are monoecious & have 4 petals, are pink, very small, & arranged in 4-flowered whorls along a spike. They are held above the water on an emerged flower spike that is 5-20 cm (about 2-8 inches) long. a. Female flowers are basal while male flowers are located distally on the same Source: Online photo gobotany inflorescence. They have a 4-lobed pistil & newenglandwild.org. EWM flowers. lack sepals & petals. EURASIAN WATERMILFOIL Myriophyllum spicatum General Characteristics 4. Unlike other watermilfoil species, EWM lacks turions, which are overwintering buds that store starch to be used for subsequent growth (Jacobs 2009). 5. Stems are slender, smooth, green, reddish-brown or pinkish-white, & can grow over 7 meters in length (Gleason & Cronquist 1991). EWM branches profusely once it reaches the water surface & forms a dense canopy (Aiken et al 1979). 6. Eurasian watermilfoil spreads & reproduces asexually by regrowth of plant fragments. EWM can also be spread by EURASIAN WATERMILFOIL Myriophyllum spicatum General Characteristics 7. Fruits produced by sexual reproduction are 2.3 mm long with 4 grooves. Each fruit is indehiscent & contains 4 nutlike seeds (Jacobs 2009). 8. Eurasian watermilfoil is a submerged, rooted perennial; roots are fibrous, often developing on plant fragments. 9. EWM is temperature tolerant, winter-hardy, & is able to overwinter in frozen lakes & ponds in northern states & Canada. It is also able to grow Source: Online photo Myciophyllum in shallow, over-heated bays. spicatum nutlets. Source:Legagneua,P.- 200 X 150. 10. EWM has reduced xylem, since water & nutrients can be taken up through leaf tissue (Hartman and Brown (1967). EURASIAN WATERMILFOIL Myriophyllum spicatum Phenology in the Great Lakes Region* • EWM breaks dormancy & begins growing shoots from root crowns when water temperatures begins increasing & approach 15C (59F) (Smith 1990). • Growth usually occurs between March & May in the Great Lakes Region (Grace 1978). • EWM can be established by April, well before other macro-phytes show growth (Grace 1978). • In the Great Lakes Region, flowering can occur in June when the plant reaches the surface of the water (Smith & Barko 1990). • Fruits are set in June (later in July & August in higher latitudes), & EWM continues fruiting until September. *Source: After Huckins, C. et. al. Arresting the spread of Eurasian Watermilfoil (Myriophyllum spicatum) in the Great Lakes. Michigan Tech Research Institute, Michigan Tech University, Ann Arbor,MI. (www.mtu.edu). EURASIAN WATERMILFOIL Myriophyllum spicatum Phenology in the Great Lakes Region* • Maximum biomass of EWM occurs shortly after the plants flower (Grace 1978). • After plants flower & fruit, leaves begin to slough off the stems & autofragmentation occurs (late summer to early fall), which allows EWM to break into many fragments that float, then sink, root, and establish new EWM beds (vegetative propagation). • In northern latitudes, the aboveground tissue dies back to the root crown in late fall then overwinter as young shoots or buds located in the root crown or as submerged fragments & seeds in the sediment (Grace 1978). *Source: After Huckins, C. et. al. Arresting the spread of Eurasian Watermilfoil (Myriophyllum spicatum) in the Great Lakes. Michigan Tech Research Institute, Michigan Tech University, Ann Arbor,MI. (www.mtu.edu). EURASIAN WATERMILFOIL Myriophyllum spicatum Life Cycle Sexual Reproduction* • EWM can reproduce from seeds. • Sexual reproduction can occur in June once the inflorescence grows above the water surface (Nichols 1975). • Female flowers open first followed by the male flowers at a later date (Aiken et al 1979). • This strategy favors cross pollination between plants to increase genetic diversity. • EWM is primarily wind pollinated (Haynes 1988) • Once eggs are pollinated, the ovaries will mature into fruits that contain 4 nutlike seeds each. • An inflorescence typically produces 12-40 seeds. • Fruits are dispersed by wind before they sink (Nichols 1976). *Source: After Huckins, C. et. al. Arresting the spread of Eurasian Watermilfoil (Myriophyllum spicatum) in the Great Lakes. Michigan Tech Research Institute, Michigan Tech University, Ann Arbor, MI. (www.mtu.edu). EURASIAN WATERMILFOIL Myriophyllum spicatum Life Cycle Sexual Reproduction* •Seeds have a long dormancy up to 7 years. • Dormancy can be broken through scarification, freezing, drying, or extreme pH (Coble & Vance 1987). •Seedlings are though to be rare, so the role sexual reproduction plays in the success of EWM is unknown. • However, sexual reproduction is responsible for hybrid watermilfoil, M. spicatum X sibiricum (Moody & Les, 2002). *Source: After Huckins, C. et. al. Arresting the spread of Eurasian Watermilfoil (Myriophyllum spicatum) in the Great Lakes. Michigan Tech Research Institute, Michigan Tech University, Ann Arbor, MI. (www.mtu.edu). HYBRID WATERMILFOIL •M. spicatum is capable of hybridizing with the native M. sibiricum to produce M. sibiricum X M. spicatum which has an intermediate number of leaf segments between the two parent species (Reznicek et al 2011). There are 238 occurrences of this hybrid in 6 states as per USGS (nas.er.usgs. gov.). •These hybrids have been documented in Michigan, Minnesota, Wisconsin, Idaho, Oregon,& Washington (Moody & Les. 2002). Source: nas.er.usgs.gov/queries/Greatlakes/Fact Sheet.aspx?Species IN=237 HYBRID WATERMILFOIL • This hybrid has also been found in Steuben County, Indiana at Big Turkey Lake according to Rod Edgell, IN DNR, at LARE Meeting, Wawasee Center, 9-25-2018. •This hybrid also occurs in Lake Wawasee and Syracuse Lake (WACF Ecology Committee Minutes 10-17- 2019). Source: nas.er.usgs.gov/queries/Greatlakes/Fact Sheet.aspx?Species IN=237 HYBRID WATERMILFOIL CONTROL • The Procellacor EC specimen label, a group 4 herbicide, lists Hybrid Eurasian Watermilfoil (M.M. spicatumspicatum XX M.M. spp.spp.) as a vascular aquatic plant controlled with in-water application with this herbicide (see table 3 in the specimen label). Also controlled with this herbicide are Eurasian Watermilfoil (M. spicatum), and Variable Watermilfoil (M. heterophyllum). Source: nas.er.usgs.gov/queries/Greatlakes/Fact Sheet.aspx?Species IN=237 PROCELLACOR EC SAFETY DATA SHEET SECTION 10 EURASIAN WATERMILFOIL Myriophyllum spicatum Life Cycle Asexual Reproduction* • EWM can reproduce asexually through plant fragmentation. EWM spreads & reproduces mainly by regrowth of plant fragments. • EWM will autofragment: • After EWM flowers, plants begin to produce layers of lignified cells at stem nodes allowing it to fragment without mechanical disturbance. • Small branch fragments break off the plant & form roots which can establish new plants. Roots grow at the nodes & fragments, later sink, and establish roots in the substrate. • Fragments that contain a node can produce a new viable plant. Fragments can stay alive for weeks out of water if kept moist. *Source: After Huckins, C. et. al. Arresting the spread of Eurasian Watermilfoil (Myriophyllum spicatum) in the Great Lakes. Michigan Tech Research Institute, Michigan Tech University, Ann Arbor, MI. (www.mtu.edu). EURASIAN WATERMILFOIL Myriophyllum spicatum Life Cycle Asexual Reproduction* •Boaters, waterfowl, & water currents readily move fragments between & within waters which is a major reason for its spread across the Unites States. Transport on boating equipment plays the largest role in introducing fragments to new waterbodies. •EWM plants can store carbohydrates in the lower stems that allows the plant to survive over the winter. When water temperature reach 50-60°F, the plant will begin growing out of the
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