''Stratiotes'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of submerged

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

commonly known as water soldiers, described as a genus by Linnaeus in 1753. Several specific names have been coined within the genus, but at present only one is recognized: ''

Stratiotes aloides ''Stratiotes aloides'', commonly known as water-soldier''Stratiotes aloides''
at the BSBI Plant Atla ...

''. native to Europe and NW Asia. ;formerly included in genus moved to other genera: ''

Enhalus ''Enhalus'' is a monotypic genus of marine flowering plants. The sole species is ''Enhalus acoroides''. ''Enhalus'' is a large seagrass native to coastal waters of the tropical Indian and Western Pacific Oceans. It is the only species of seag ...

Hydrocleys

Ottelia ''Ottelia'' is a genus of an aquatic plant family Hydrocharitaceae described as a genus in 1805. The genus is native to tropical and subtropical regions of Africa, Asia, South America, and Australia.Cook, C.D.K. and Urmi- Konig, K. (1984A revisio ...

'' # ''Stratiotes acoroides -

Enhalus acoroides ''Enhalus'' is a monotypic genus of marine flowering plants. The sole species is ''Enhalus acoroides''. ''Enhalus'' is a large seagrass native to coastal waters of the tropical Indian and Western Pacific Oceans. It is the only species of seag ...

'' # ''Stratiotes alismoides -

Ottelia alismoides ''Ottelia alismoides'', commonly known as duck lettuce, is a species of aquatic plant native to Asia and northern Australia. Due to habitat loss and deterioration, it is endangered in China and Japan, although it is an invasive weed in America. I ...

'' # ''Stratiotes nymphoides - Hydrocleys nymphoides'' # ''Stratiotes quinquealatus -

Description

The leaves are

serrate Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pr ...

and very brittle, breaking easily when handled. Reproduction is generally by offsets, which may number five or more per plant. In the UK, male plants have rarely if ever been recorded, although some

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

flowers have been recorded from more southerly locations. Sexual reproduction is not known to occur. A characteristic of the genus is the habit of the plants rising to the surface at flowering time.

Ecology

The plant appears to be associated with calcareous waters and there is a suggestion that changing levels of

calcium carbonate Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...

on the leaves may explain the floating and submerging behaviour. The rare

dragonfly A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threat ...

, the

Norfolk hawker ''Aeshna isoceles'' (or ''isosceles'') is a small hawker dragonfly that is found in Europe, mostly around the Mediterranean, and the lowlands of North Africa. Its common name in English is green-eyed hawker. In the United Kingdom it is a localise ...

(''Aeshna isosceles''), relies on the presence of ''Stratiotes aloides'' as a food source for the smaller

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s on which it feeds. The plant is very winter hardy.

Fossil record

Several

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

seeds of †''Stratiotes kaltennordheimensis'' have been extracted from

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petr ...

samples of the

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

fresh water deposits in Nowy Sacz Basin,

West Carpathians The Western Carpathians () are a mountain range and geomorphological province that forms the western part of the Carpathian Mountains. The mountain belt stretches from the Low Beskids range of the Eastern Carpathians along the border of Poland w ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...

.Łańcucka-Środoniowa M.: Macroscopic plant remains from the freshwater Miocene of the Nowy Sącz Basin (West Carpathians, Poland) zczątki makroskopowe roślin z miocenu słodkowodnego Kotliny Sądeckiej (Karpaty Zachodnie, Polska) Acta Palaeobotanica 1979 20 (1): 3-117.

Uses

''Stratiotes aloides'' is commonly used in cool water

ponds A pond is a small, still, land-based body of water formed by pooling inside a depression, either naturally or artificially. A pond is smaller than a lake and there are no official criteria distinguishing the two, although defining a pond t ...

and

aquariums An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

References

External links

Invading Species.com
Partnership between the Ontario Ministry of Natural Resources and the Ontario Federation of Anglers and Hunters Hydrocharitaceae Hydrocharitaceae genera Aquatic plants Monotypic Alismatales genera Dioecious plants {{alismatales-stub