| Potamogeton polygonifolius | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Alismatales |
| Family: | Potamogetonaceae |
| Genus: | Potamogeton |
| Species: | P. polygonifolius |
| Binomial name | |
| Potamogeton polygonifolius Pourr. | |
Potamogeton polygonifolius or bog pondweed, is an aquatic plant. It is found in shallow, nutrient-poor, usually acid standing or running water, bogs, fens and occasionally ditches.
Bog pondweed is a perennial, growing from creeping rhizomes. The stems are up to 0.7 m long, terete and unbranched. [1] The submerged leaves are long (60–160 mm) and fairly narrow (2.5–24 mm), delicate and translucent with long (14–80 mm)petioles, [1] tending to decay rather early in the season, typically once the floating leaves appear. The floating leaves are opaque, 40-105 x 15–70 mm, usually brownish or dark green in colour with a pink tint when young, with inconspicuous secondary veins. [1] There are no turions.
The inflorescences are up to 42 mm long and produce numerous small greenish flowers. The fruits are 1.9-2.6 mm x 1.4-1.9 mm, larger than P. coloratus but smaller than P. natans. [1]
Bog pondweed occurs both as terrestrial plants in seeps and wet moss, and as aquatic forms, and is very variable. Terrestrial forms in particular can be very difficult to identify. It is most likely to be confused with P. natans which it resembles in general habit, but can usually be distinguished by the presence of submerged leaves (these are reduced to strap-like phyllodes in P.natans) and the absence of a discoloured mark at the base of the floating leaves. The submerged leaves of P. alpinus can be similar, but these are sessile. Although a common plant, bog pondweed does not seem to hybridise readily with other pondweeds, though hybrids with P. natans (P. × gessnacensisG.Fisch.), P. gramineus , P. alpinus (P. × spathulatusSchrad. ex W.D.J.Koch & Ziz), P. berchtoldii (P. × rivularisGillot)and P. pusillus have been recorded. [1]
Potamogeton polygonifolius is mainly restricted to western Europe (Britain, Ireland, France, Netherlands, Belgium, Denmark). It is more localised in the rest of its range including Northern Iberia, Germany, mainland Italy, Sicily, southern Scandinavia, the Baltic states, the Balkans and eastern Europe. [2] There are outlying populations in North Africa (Morocco, Algeria), Orkney, Shetland, the Faroes and Newfoundland, and fossils have been found in Russia. [2] The taxonomic status of populations in the Himalayas requires confirmation. [2] A record from China was based on a misidentification of P. distinctus . [3]
In Britain and Ireland, this is one of the commonest pondweeds, occurring in almost any wet or semi-wet oligotrophic and / or acidic habitat so long as flow is not too rapid. It may be found in lakes, slow-flowing rivers, ponds, ditches, seeps and among bog mosses ( Sphagnum ). As its name suggests, it is common in areas of blanket bog [1] [4] but may also occur in secondary habitats such as unshaded drainage ditches in bogs [4] and forest plantations. In British rivers it typically grows with other soft-water species such as Ranunculus flammula , Carex nigra , C. rostrata , Scapania undulata and Equisetum fluviatile . [5] In lakes it tends to occur in base-poor, oligotrophic waters with species such as Littorella uniflora, Sphagnum spp., Lobelia dortmanna and Isoetes lacustris [6] especially with a peaty substrate.
Potamogeton polygonifolius is tolerant of acid conditions and therefore has not been affected by the widespread acidification of upland habitats in Britain. However, in very acidified pools in Holland (pH < 5), catchment liming increased the abundance of this and other threatened species. [7] Although it shows a strong preference for soft waters, [8] bog pondweed may also occur in calcareous but low-nutrient habitats. [9] In lowland areas it is more scattered and has declined in southern and eastern England due to nutrient enrichment. [9]
In Central Europe, Potamogeton polygonifolius is threatened, and is considered endangered in Germany, Poland, Switzerland, the Czech Republic. [4] and Luxemburg. [10] However, remaining populations in this area are still strong and reproduce freely. [4] Bog pondweed is also a Red List species in Holland. [7]
Bog pondweed is not in general cultivation, although it is easy to grow. Its preference for shallow water makes it very suitable for a garden pond, but it would probably be difficult to establish in high nutrient, hard water areas.
Potamogeton is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed. The genus name means "river neighbor", originating from the Greek potamos (river) and geiton (neighbor).
This article gives an overview of the aquatic communities in the British National Vegetation Classification system.
Luronium natans is a species of aquatic plant commonly known as the floating water-plantain. It is the only recognized species in the genus Luronium, native to western and central Europe, from Spain to Britain to Norway east to Ukraine.
Potamogeton crispus, the curled pondweed or curly-leaf pondweed, is a species of aquatic plant native to Eurasia but an introduced species and often a noxious weed in North America.
Potamogeton natans, commonly known as broad-leaved pondweed, floating pondweed, or floating-leaf pondweed, is an aquatic species in the genus Potamogeton native to quiet or slow-flowing freshwater habitats throughout the Holarctic Kingdom.
Potamogeton perfoliatus is a perennial aquatic plant in the family Potamogetonaceae occurring in both standing and flowing freshwater habitats. It is widely distributed globally, occurring in all continents except South America and Antarctica.
Potamogeton praelongus, commonly known as whitestem pondweed in North America and Long-stalked Pondweed in Britain, is a large, perennial aquatic plant in the family Potamogetonaceae. It is widely distributed in lakes and rivers in the northern hemisphere, but is sensitive to poor water quality.
Potamogeton coloratus, the fen pondweed, is an aquatic plant in the genus Potamogeton. It is found in shallow peaty calcareous lakes, ponds and ditches, commonly associated with lowland fens.
Potamogeton lucens, or shining pondweed, is an aquatic perennial plant native to Eurasia and North Africa. It grows in relatively deep, still or slow-flowing, calcareous freshwater habitats.
Potamogeton alpinus is a species of perennial aquatic plant known by the common names alpine pondweed and red pondweed. It is widespread in the northern hemisphere in both rivers and lakes with good water quality.
Potamogeton epihydrus is a perennial aquatic plant known by the common names ribbonleaf pondweed and Nuttall's pondweed, and American pondweed in the United Kingdom. It is native to much of North America, where it grows in water bodies such as ponds, lakes, ditches, and slow-moving streams.
Potamogeton gramineus is a species of aquatic plant known by the common name various-leaved pondweed, variableleaf pondweed, grass-leaved pondweed or grassy pondweed, native to the northern hemisphere where it grows in shallow, clean water.
Potamogeton pusillus is a species of aquatic plant known by the common names small pondweed, lesser pondweed or least pondweed. It occurs in standing and slow-flowing freshwater habitats throughout the Northern Hemisphere.
Potamogeton compressus is a species of aquatic plant known by the common names grass-wrack pondweed, flatstem pondweed and eel-grass pondweed.
Potamogeton obtusifolius, known as blunt-leaved pondweed, is an aquatic plant in the genus Potamogeton. It grows mainly in mesotrophic to eutrophic lakes, ponds and ditches, rarely in brackish water. It occurs primarily in Central Europe, the British Isles, Fennoscandia and eastern North America.
Potamogeton berchtoldii, common name small pondweed is an aquatic plant.
Potamogeton acutifolius is a European species of aquatic plant in the family Potamogetonaceae, known by the common name sharp-leaved pondweed. It is threatened and declining in at least part of its range.
Potamogeton × griffithii is a hybrid pondweed between Potamogeton alpinus and Potamogeton praelongus. It occurs in oligotrophic, moderate alkalinity lakes.
Potamogeton trichoides is a species of aquatic plant known by the common name hairlike pondweed, native to Europe and western Asia where it grows in calcareous, usually nutrient-rich standing or slow-flowing water.
Potamogeton friesii, known as flat-stalked pondweed, or Fries' pondweed, is an aquatic plant in the genus Potamogeton. It grows mainly in mesotrophic to eutrophic rivers, lakes, ponds and ditches, rarely in brackish water. It occurs in North America, Europe, western Asia and a few scattered locations elsewhere in Asia.
