Potamogeton × griffithii is a sterile hybrid pondweed between red pondweed Potamogeton alpinus and long-stalked pondweed Potamogeton praelongus. It occurs in clear, oligotrophic, low to moderate alkalinity lakes. It was discovered in 1882 in Llyn Anafon, North Wales by J.E. Griffith, a Victorian botanist, and was named after him by the noted pondweed expert Arthur Bennett.
Although intermediate in character between the parents, Potamogeton x griffithii is unlikely to be confused with either. It has long, branched stems to at least 1.7 m[1] and probably longer, growing from slender perennial rhizomes. The translucent mid to deep green leaves are typically between 120 and 240 mm long, occasionally reach 330 mm and are 10–25 mm wide and hooded at the tip.[1] The leaves are sessile, sometimes slightly clasping the stem but shortly petiolate leaves may also be present. The stipules are persistent, open, colourless with a milky tinge, and opaque when dry.[1] Floating leaves may be produced and are relatively narrow, 85-105 x 13–25 mm. Turions are absent. The inflorescences are 10–20 mm long and have inconspicuous greenish flowers on robust peduncles 45–190 mm long.[1] Fruits are not produced.[1]
Potamogeton × griffithii is relatively easy to identify. It is larger than P. alpinus, and the branching habit immediately distinguishes the two.[1] The leaf tip is also more distinctly hooded. The leaves are relatively longer than P. praelongus and P. perfoliatus, and mostly do not clasp the stem. The stems are also markedly more slender than P. praelongus and do not develop the characteristic 'zigzag' pattern caused by the stem changing the angle of growth at each node.
DistributionEdit
Potamogeton × griffithii is a rare hybrid. As well as its type locality in Wales, it has also been found in a lake in the north of Ireland, and in two lakes in western Scotland.[1] In North America, it has been recorded from three locations in the USA, all in Wisconsin, and in Canada (Alberta).[2]
Ecological requirements and conservationEdit
In Llyn Anafon, Potamogeton x griffithii grows in clear, oligotrophic water with some basic influence, 0.75-3.2 m deep, among beds of Chara virgata[3] and in shallower water, in a more diverse community including Nitella opaca, N. translucens, Utricularia minor, Juncus bulbosus, Isoetes lacustris and Callitriche brutia var. hamulata. One of the parents, Potamogeton alpinus, grows in the inflow stream, but P. praelongus has never been recorded in or near the lake. It is likely that the beds of P. × griffithii here have been established for centuries, perhaps even millennia. P. praelongus has not been recorded at any of the British and Irish sites where P. × griffithii grows.[1][3]
Potamogeton × griffithii is classified as Vulnerable by both the British[4] and Welsh[5] Vascular Plant Red Lists due to the low number of sites in which it occurs.
CultivationEdit
Potamogeton × griffithii is not in general cultivation, though like both of its parents it is an attractive plant. A patch has been established in a wildlife pond in Bangor University's Treborth Botanic Gardens, where it grows well on a sandy substrate in about 1 m depth. In common with other pondweeds of this group it roots poorly from stem cuttings and is best propagated by division of the rhizomes. Good water quality is needed to reduce the risk of turbid water or growth of blanket weed.
ReferencesEdit
^ abcdefghPreston C.D. (1995). Pondweeds of Great Britain and Ireland. BSBI Handbook No. 8. Botanical Society of the British Isles, London.
^ abBurgess A., Goldsmith B., Hatton-Ellis T.W. 2013. Site Condition Assessments of Welsh SAC and SSSI Standing Water Features 2007-2012. CCW Contract Science Report No. 983. Countryside Council for Wales, Bangor.
^Cheffings C.M., Farrell, L. (Eds), Dines T.D., Jones R.A., Leach S.J., McKean D.R., Pearman D.A., Preston C.D., Rumsey F.J., Taylor I. 2005. The Vascular Plant Red Data List for Great Britain. Species Status, 7, 1-116. Joint Nature Conservation Committee, Peterborough.
^. Archived from the original on 2014-11-12. Retrieved 2014-11-15.
External linksEdit
August 26, 2023
potamogeton, griffithii, hybrid, pondweed, between, potamogeton, alpinus, potamogeton, praelongus, occurs, oligotrophic, moderate, alkalinity, lakes, scientific, classificationkingdom, plantaeclade, tracheophytesclade, angiospermsclade, monocotsorder, alismata. Potamogeton griffithii is a hybrid pondweed between Potamogeton alpinus and Potamogeton praelongus It occurs in oligotrophic moderate alkalinity lakes Potamogeton griffithiiScientific classificationKingdom PlantaeClade TracheophytesClade AngiospermsClade MonocotsOrder AlismatalesFamily PotamogetonaceaeGenus PotamogetonSpecies P griffithiiBinomial namePotamogeton griffithiiA Bennett Contents 1 Description 2 Distribution 3 Ecological requirements and conservation 4 Cultivation 5 References 6 External linksDescription EditPotamogeton griffithii is a sterile hybrid pondweed between red pondweed Potamogeton alpinus and long stalked pondweed Potamogeton praelongus It occurs in clear oligotrophic low to moderate alkalinity lakes It was discovered in 1882 in Llyn Anafon North Wales by J E Griffith a Victorian botanist and was named after him by the noted pondweed expert Arthur Bennett Although intermediate in character between the parents Potamogeton x griffithii is unlikely to be confused with either It has long branched stems to at least 1 7 m 1 and probably longer growing from slender perennial rhizomes The translucent mid to deep green leaves are typically between 120 and 240 mm long occasionally reach 330 mm and are 10 25 mm wide and hooded at the tip 1 The leaves are sessile sometimes slightly clasping the stem but shortly petiolate leaves may also be present The stipules are persistent open colourless with a milky tinge and opaque when dry 1 Floating leaves may be produced and are relatively narrow 85 105 x 13 25 mm Turions are absent The inflorescences are 10 20 mm long and have inconspicuous greenish flowers on robust peduncles 45 190 mm long 1 Fruits are not produced 1 Potamogeton griffithii is relatively easy to identify It is larger than P alpinus and the branching habit immediately distinguishes the two 1 The leaf tip is also more distinctly hooded The leaves are relatively longer than P praelongus and P perfoliatus and mostly do not clasp the stem The stems are also markedly more slender than P praelongus and do not develop the characteristic zigzag pattern caused by the stem changing the angle of growth at each node Distribution EditPotamogeton griffithii is a rare hybrid As well as its type locality in Wales it has also been found in a lake in the north of Ireland and in two lakes in western Scotland 1 In North America it has been recorded from three locations in the USA all in Wisconsin and in Canada Alberta 2 Ecological requirements and conservation EditIn Llyn Anafon Potamogeton x griffithii grows in clear oligotrophic water with some basic influence 0 75 3 2 m deep among beds of Chara virgata 3 and in shallower water in a more diverse community including Nitella opaca N translucens Utricularia minor Juncus bulbosus Isoetes lacustris and Callitriche brutia var hamulata One of the parents Potamogeton alpinus grows in the inflow stream but P praelongus has never been recorded in or near the lake It is likely that the beds of P griffithii here have been established for centuries perhaps even millennia P praelongus has not been recorded at any of the British and Irish sites where P griffithii grows 1 3 Potamogeton griffithii is classified as Vulnerable by both the British 4 and Welsh 5 Vascular Plant Red Lists due to the low number of sites in which it occurs Cultivation EditPotamogeton griffithii is not in general cultivation though like both of its parents it is an attractive plant A patch has been established in a wildlife pond in Bangor University s Treborth Botanic Gardens where it grows well on a sandy substrate in about 1 m depth In common with other pondweeds of this group it roots poorly from stem cuttings and is best propagated by division of the rhizomes Good water quality is needed to reduce the risk of turbid water or growth of blanket weed References Edit a b c d e f g h Preston C D 1995 Pondweeds of Great Britain and Ireland BSBI Handbook No 8 Botanical Society of the British Isles London USDA Plants Profile Potamogeton griffithii a b Burgess A Goldsmith B Hatton Ellis T W 2013 Site Condition Assessments of Welsh SAC and SSSI Standing Water Features 2007 2012 CCW Contract Science Report No 983 Countryside Council for Wales Bangor Cheffings C M Farrell L Eds Dines T D Jones R A Leach S J McKean D R Pearman D A Preston C D Rumsey F J Taylor I 2005 The Vascular Plant Red Data List for Great Britain Species Status 7 1 116 Joint Nature Conservation Committee Peterborough Dines T D 2008 A Vascular Plant Red List for Wales Plantlife International Salisbury Archived from the original on 2014 11 12 Retrieved 2014 11 15 External links Edit Retrieved from https en wikipedia org w index php title Potamogeton griffithii amp oldid 1047616787, wikipedia, wiki, book, books, library,
