Water SoldierScientific NameStratiotes aloides L.AppearancePerennial, submerged aquatic plant with flowering and non-flowering forms; the flowering form often rises seasonally to the water’s surface and is semi-emergent (above water surface) when fully flowering. Roots are unbranched and do not always attach to the substrate.LeavesLong, linear or narrowly triangular, stalkless, sharply serrated, length 40-110 cm (approx. 16-43 in.); leaves form a large rosette (whorl) with submerged leaves flaccid, brittle, thin and longer than the thick, rigid, emergent leaves that rise above the water surface.Flowers and FruitsWhen present, flowers rise above the plant and have 3 white to greenish sepals and 3 white petals. Male and female flowers occur on separate plants and look similar. Fruit is a barrel-shaped, berry-like capsule containing up to 24 seeds.Similar SpeciesResembles an aloe plant.HabitatOften found in ponds and ditches at depths up to 5 m (approx. 16.5 ft.). Not tolerant of high flow velocity or great fluctuations in water levels. Also found in fens, oxbows and inlets of lakes.Introduced RangeIn Ontario: in southern Ontario in the Trent River portion of the Trent-Severn Waterway near the hamlet of Trent River, Ontario. This is the only known population in North America.Native RangeWestern Asia, east to central Siberia; eastern, central and northern Europe; possibly western Europe as far west as Ireland.Pathway of Introduction and SpreadMay be part of the ornamental garden trade. Spread is by plant fragments that break off and travel in water currents. May be unintentionally spread by watercraft.ImpactsSharp, serrated leaf edges easily cut swimmers and individuals who handle water soldier plants. Forms dense mats of floating vegetation that crowd native vegetation. May modify surrounding water chemistry and impact phytoplankton and other aquatic organisms.Invasive Species Act, 2015To prevent the introduction and further spread of this unwanted invader in the province, Ontario has regulated it as a prohibited invasive species under the Invasive Species Act. For more information on the Invasive Species Actand regulations visit www.ontario.ca/invasionON.ReferencesOntario Ministry of Natural Resources. 2010. Field Guide to Aquatic Invasive Species, 3rd Edition. Queen’s Printer for Ontario. Ontario, Canada.