water soldier
(Stratiotes aloides)
This species is a Cultivar and may be non-native across its range in the United States
Water Soldier
Scientific Name
Stratiotes aloides L.
Appearance
Perennial, 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.
Leaves
Long, 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 Fruits
When 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 Species
Resembles an aloe plant.
Habitat
Often 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 Range
In 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 Range
Western Asia, east to central Siberia; eastern, central and northern Europe; possibly western Europe as far west as Ireland.
Pathway of Introduction and Spread
May 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.
Impacts
Sharp, 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, 2015
To 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.
References
Ontario Ministry of Natural Resources. 2010. Field Guide to Aquatic Invasive Species, 3rd Edition. Queen’s Printer for Ontario. Ontario, Canada.
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Lists - This map identifies those states that have this species on their invasive species list or law.
Invasive Listing Sources
- Alabama Noxious Weeds - Class C Noxious Weed
- Alberta Fisheries Act
- Florida Noxious Weeds
- Indiana Invasive Species Council - Invasive Plant List
- Michigan’s Invasive Species Watch List
- Michigan’s Prohibited and Restricted Species
- Minnesota DNR invasive species list
- New Jersey Invasive Species Strike Team 2017 Invasive Species List
- Ontario’s Invading Species Awareness Program Tracked Species List
- Oregon Noxious Weeds
- Wisconsin Noxious Weeds
- Wisconsin's Invasive species rule – NR 40
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Superorder: Lilianae |
| Order: Alismatales |
| Family: Hydrocharitaceae |
| Genus: Stratiotes |
| Stratiotes aloides |
References
Common Name Reference: Weed Science Society of America Common Names List
Scientific Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.