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Water chestnut (Trapa natans)
Photo credit: Jörg Hempel;   CC BY-SA 2.0

Water Soldier

(Stratiotes aloides)

Report this Species!

If you believe you have found this species anywhere in Pennsylvania, please report your findings to iMapInvasives by submitting an observation record.

Species at a Glance

Water soldier is an invasive perennial aquatic plant that is native to Europe and northwest Asia. The only known wild populations in North America occur in Ontario, within the Trent River (near the Hamlet of Trent River), and the Black River (near Sutton). Water soldier is used as an ornamental plant in water gardens, the likely source of its introductions to Ontario.

Similar Species

Upon first glance, water soldier may resemble plants such as arrowheads, bur-reeds, or (when submerged) eel-grass; however, the sharp serrated leaves and rosette growing habit should aid observers in distinguishing it from other plants.


As an aquatic plant, water soldier is found in inlets of sheltered bays and large lakes. It prefers backwaters, sluggish canals, and ditches.


Native to Europe, water soldier was likely introduced into North America as an ornamental. In 2008, it was first found outside its native range in the Trent River in Ontario, Canada. Water solider's current distribution in North America is known only in Ontario.

Environmental Impacts

This loosely rooted aquatic plant forms dense mats which crowd out native species and decrease biodiversity. The sharp serrated leaves are a danger to swimmers and others who handle the plant. It can potentially alter water chemistry which may harm phytoplankton and other aquatic organisms.

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