Potamogeton
| Potamogeton | |
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| Potamogeton perfoliatus | |
| Scientific classification | |
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| Genus: | Potamogeton |
| Species | |
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80-100, see text | |
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 (Elodea canadensis). The genus name means "river neighbor", originating from the Greek potamos (river) and geiton (neighbor).[1][2]
Morphology
Potamogeton species may be large or very small. Plants are sometimes annuals but are often perennial and typically produce rhizomes which are the common over-wintering form. Many species also produced specialised overwintering buds called turions which may be borne on the rhizome, on the stem or on stolons from the rhizome. The leaves are alternate, which contrasts with the closely related genus Groenlandia where the leaves are opposite or whorled.
In many species, all the leaves are submerged and in these cases the leaves are typically thin and translucent. Some species, especially in ponds and very slow moving waters, have floating leaves which tend to be more leathery.
Diagnostic of most species of Potamogeton is the presence of a delicate membranous sheathing scale at the leaf axil. This may be wholly attached, partly attached or free of the leaf and it may have inrolled margins or appear as a tube. The flowers, which are often overlooked are composed of 4 rounded segments borne in a spike.
Taxonomy
Potamogeton species are found throughout the world where there is standing or running water. There are estimated to be around 90 species but hybridisation provides an added complexity to the taxonomy. At least 26 hybrids have been observed in the British Isles alone.[2]
History
Alfred Fryer became interested in Potamogeton in the 1880s, and was a recognised authority on the genus. The first parts of his work The Potamogetons (Pond Weeds) of the British Isles were published in 1898. His death intervened, and the work was completed by Arthur Bennett (1843-1929). Robert Morgan (1863-1900) illustrated Fryer's contribution to the monograph, his colour plates drawing praise from later critics. [3][4]
Non-hybridised species
- P. acutifolius Link ex Roem. & Schult.
- P. alpinus Balb.
- P. amplifolius Tuck.
- P. antaicus Hagstr.
- P. australiensis A.Benn.
- P. berchtoldii Fieber
- P. bicupulatus Fernald
- P. biformis Hagstr.
- P. brasiliensis A.Benn.
- P. chamissoi A.Benn.
- P. cheesemanii A.Benn.
- P. chongyangensis W.X.Wang
- P. clystocarpus Fernald
- P. coloratus Hornem.
- P. compressus L.
- P. confervoides Rchb.
- P. crispus L.
- P. cristatus Regel & Maack
- P. delavayi A.Benn.
- P. distinctus A.Benn.
- P. diversifolius Raf.
- P. drummondii Benth.
- P. dunicola Tur
- P. epihydrus Raf.
- P. faxonii Morong
- P. ferrugineus Hagstr.
- P. floridanus Small
- P. foliosus Raf.
- P. fontigenus Y.H.Guo, X.Z.Sun & H.Q.Wang
- P. friesii Rupr.
- P. fryeri A.Benn.
- P. gayi A.Benn.
- P. gramineus L.
- P. hagstromii A.Benn.
- P. hillii Morong
- P. hoggarensis Dandy
- P. illinoensis Morong
- P. intortusifolius J.B.He, L.Y.Zhou & H.Q.Wang
- P. iriomotensis Masam.
- P. juzepczukii P.I.Dorof. & Tzvelev
- P. leptanthus Y.D.Chen
- P. linguatus Hagstr.
- P. lucens L.
- P. maackianus A.Benn.
- P. mandschuriensis (A.Benn.) A.Benn.
- P. marianensis Cham. & Schltdl.
- P. montevidensis A.Benn.
- P. nanus Y.D.Chen
- P. natans L.
- P. nodosus Poir.
- P. nomotoensis Kadono & T.Nog.
- P. oakesianus J.W.Robbins
- P. obtusifolius Mert. & W.D.J.Koch
- P. ochreatus Raoul
- P. octandrus Poir.
- P. ogdenii Hellq. & R.L.Hilton
- P. oxyphyllus Miq.
- P. papuanicus G.Wiegleb
- P. paramoanus R.R.Haynes & Holm-Niels.
- P. parmatus Hagstr.
- P. pedersenii Tur
- P. perfoliatus L.
- P. polygonifolius Pourr.
- P. praelongus Wulfen
- P. pseudopolygonus Hagstr.
- P. pulcher Tuck.
- P. punense A.Galán
- P. pusillus L.
- P. quinquenervius Hagstr.
- P. reniacoensis Sparre
- P. richardii Solms
- P. richardsonii (A.Benn.) Rydb.
- P. robbinsii Oakes
- P. rutilus Wolfg.
- P. sarmaticus Mäemets
- P. schweinfurthii A.Benn.
- P. sclerocarpus K.Schum.
- P. sibiricus A.Benn.
- P. skvortsovii Klinkova
- P. solomonensis G.Wiegleb
- P. spathuliformis (J.W.Robbins) Morong
- P. spirilliformis Hagstr.
- P. spirillus Tuck.
- P. stenostachys K.Schum.
- P. strictifolius A.Benn.
- P. suboblongus Hagstr.
- P. sulcatus A.Benn.
- P. tennesseensis Fernald
- P. tepperi A.Benn.
- P. tricarinatus F.Muell. & A.Benn.
- P. trichoides Cham. & Schltdl.
- P. tubulatus Hagstr.
- P. ulei K.Schum.
- P. uruguayensis A.Benn. & Graebn.
- P. vaseyi J.W.Robbins
- P. wrightii Morong
- List source : [5]
Hybridised species
- P. × anguillanus Koidz.
- P. × angustifolius J.Presl
- P. × angustifolius Miki
- P. × argutulus Hagstr.
- P. × attenuatus Hagstr.
- P. × babingtonii A.Benn.
- P. × billupsii Fryer
- P. × cadburyae Dandy & G.Taylor
- P. × cognatus Asch. & Graebn.
- P. × cooperi (Fryer) Fryer
- P. × faurei (A.Benn.) Miki
- P. × fluitans Roth
- P. × franconicus G.Fisch.
- P. × gessnacensis G.Fisch.
- P. × griffithii A.Benn.
- P. × grovesii Dandy & G.Taylor
- P. × haynesii Hellq. & G.E.Crow
- P. × kamogawaensis Miki
- P. × kyushuensis Kadono & Wiegleb
- P. × lanceolatifolius (Tiselius) C.D.Preston
- P. × lanceolatus Sm.
- P. × leptocephalus Koidz.
- P. × lintonii Fryer
- P. × malainoides Miki
- P. × mariensis Papch.
- P. × mysticus Morong
- P. × nericius Hagstr.
- P. × nerviger Wolfg.
- P. × nitens Weber
- P. × olivaceus Baagøe ex G.Fisch.
- P. × orientalis Hagstr.
- P. × philippinensis A.Benn.
- P. × prussicus Hagstr.
- P. × pseudofriesii Dandy & G.Taylor
- P. × rectifolius A.Benn.
- P. × salicifolius Wolfg.
- P. × schreberi G.Fisch.
- P. × scoliophyllus Hagstr.
- P. × sparganiifolius Laest. ex Fr.
- P. × spathulatus Schrad. ex W.D.J.Koch & Ziz
- P. × subsessilis Hagstr.
- P. × sudermanicus Hagstr.
- P. × undulatus Wolfg.
- P. × vaginans (Bojer ex A.Benn.) Hagstr.
- P. × varians Morong
- P. × variifolius Thore
- P. × vepsicus A.A.Bobrov & Chemeris
- List source : [5]
Ecology
Potamogeton species are found worldwide in many aquatic ecosystems. They are important as food and habitat for animals.[2][6] Most species are not weedy, but a few can become troublesome, such as curly-leaf pondweed (Potamogeton crispus).[7]
References
- ^ Robert F. Thorne (2012). "Jepson Manual treatment for Potamogetonaceae (Pondweed Family)". Jepson Manual Online. University & Jepson Herbaria; Regents of the University of California. Retrieved January 6, 2012.
- ^ a b c "Potamogeton". Flora of North America. 22. eFloras. Retrieved January 6, 2012.
- ^ http://www.watsonia.org.uk/Wats16p217.pdf
- ^ http://www.meiosis.org.uk/botanists/alfred-fryer-1826-1912/
- ^ a b "Potamogeton". The Plant List; Version 1. (published on the internet). Royal Botanic Gardens, Kew and Missouri Botanical Garden. 2010. Retrieved January 6, 2012.
- ^ "Pondweeds: Potamogeton species". Center for Aquatic and Invasive Plants; University of Florida / IFAS. 2011. Retrieved January 6, 2012.
- ^ "Curly leaf pondweed: Potamogeton crispus L." Center for Invasive Species and Ecosystem Health. May 4, 2010. Retrieved January 6, 2012.