Potamogeton praelongus Wulfen
Conservation status: C
First record: HE Lowe, 1833
Characteristic of larger fenland drains and of rivers, also recorded from clay and gravel pits. It was known to earlier generations of botanists from the R. Cam near Cambridge, and it was probably one of the water–weeds which in the 1890s periodically blocked the river at Newnham until cleared by the Cam Conservators or by Prof. George Darwin's gardener and his boy. (Keynes,1984). P. praelongus is no longer found in the Cam here nor in many of the localities in which it was recorded up to the mid–1950s. It is still at Wicken Fen. CD Preston. 37
R. Great Ouse, Holywell, 34–70–, SM Walters, 1953.
Abundant in the Ouse at Holywell, Hunts–Cambs boundary. 25.7.1953. DE Coombe, Card Index.
N bank Ouse and railway line near Earith, 39.74, AO Chater, 2.7.1955. 38
Near Chatteris, A Fryer, 1885, det Dandy & Taylor, BM.
Forty Foot Drain, nr Grooms Corner, Horseway, A Fryer, 3.4.1890, BM.
Chatteris, by Grooms Corner, Horseway, AF.ann.
40–foot, AF.cat.
40–foot at Doddington, [20.9.1884] AF.ann.
40–foot nr Chatteris, JE Lousley, 6.6.1933, det Dandy & Taylor, RNG. K.
Doddington, 4 foot ditch to W of rd running between the fields, 385.895 AO Chater, 6.6.1955. 39
Twenty Foot River, nr Coates, A Fryer, 3.11.1884, BM.
Benwick, 10–foot ditch to E of road, 311.930, AO Chater, 6.6.1955. 45
R. Cam near Cambridge, HE Lowe, 1833, WAR.
River Cam near Cambridge, CC Babington, 7.9.1849, det. Dandy & Taylor, CGE.
Dist.1 often found floating down the river at Cambridge when the millers cut the weeds, its place of growth being a short distance above Sheeps Green (in district 3) (1849). 3. In the river just above Sheeps Green. Bab.MS.Fl.3:785.
[Dist.] 1. Often found floating down the river. 3. In the river just above Sheep's Green, Cambridge. Bab.1860,249.
In the Cam, near Cambridge. C.C.B. Bot.Gaz. (Oct.1849)1:276.
Near Cambridge, n.c., 1842, ex Hb SH Bickham, det Dandy & Taylor, CGE.
In the river at Cambridge, AF.ann.
R Cam near Cambridge, FR Tennant, 1897, det. Dandy & Taylor, CGE.
Floating down the Cam below Pike and Eel, Mills ann.
R. Cam, Cambridge, T Foggitt, 21.6.1933, HDD.
R. Cam near Cambridge, JE Lousley, 1945, RNG.
Locally abundant in R. Cam above Cambridge as far as Byron's Pool, junction of Snobs' Stream and University Bathing Sheds, EA George, 1940.
In the Cam at Cambridge Hb DEC/244– a detached fragment stranded on the bank after a slight rise & fall in the river at Midsummer Common, 7.3.1946. Seen down as far as Fen Ditton, 2.3.1946 [sic]. DE Coombe, Card Index.
R. Cam, Midsummer Common, 7.3.1946, DE Coombe Herbarium No. 244.
Abundant up river at Coe fen, 28.6.1949. DE Coombe, Card Index.
Bourn Brook near Byron's pool, EA George, 1940.
Grantchester Meadows, DM Griffin & DJ Griffiths, 12.8.1952, det. Dandy & Taylor, CGE.
Grantchester Meadows, DA Cadbury, 1952, CGE.
R. Cam, Grantchester, in quantity, CC Townsend, 3.8.1959, conf. CD Preston, K.
Hauxton, 43–52–, G Crompton & PH Oswald, et al, 26.6.1995, [unconfirmed] [R].
The Backs, near Magdalene, PH Oswald, 4.6.1954.
Near Cambridge, close to bridge at Chesterton, (between 1925–1956) Edith Rawlins ann. 46
Chesterton, n.c., 1857, det Dandy & Taylor, NCE.
Chesterton, F Druce, 16.6.1927, det Dandy & Taylor, BM.
R.Cam, Chesterton, DM Heath, 1935, det Dandy & Taylor, BIRM.
Baitsbite. Bab.ann.Relhan,69.
Baitsbite. Bab.1860,249 & Bab.MS.Fl.3:785.
Baitsbite, HD ann.
Common between Chesterton and Baitsbite, EF Warburg, 1939.
R. Cam below Baitsbite, EA George, 1940.
Common in R. Cam between Baits Bite and Chesterton, E.F.Warburg, 1939.
R. Cam below Baits Bite to Clayhithe, EA George, 1940.
R.Cam, 47.60, (from boat), SM Walters, 7.1954.
In the ballast–pits near the railway junction at Chesterton. Rev Dr Cookson. Bab.1860,249 & Bab.MS.Fl.3:785.
R. Cam, Fen Ditton, FJA Hort, 31.10.1849, det Dandy & Taylor, BM. 47
Counter Drain, Sutton Gault, A Fryer, 12.5.1887, & 13.9.1891, det. Dandy & Taylor, BM.
Counter Wash, Sutton Gault to Welches Dam, AF.ann.
Upper Delphs, 40–73–, and Flat Bridge, Aldreth, 41–73–, AO Chater, 2.7.1955. 48
Old Bedford River, Welches Dam, A Fryer, 1884–8, BM. AF.cat.
Forty Foot Drain, Welches Dam, A Fryer, 1884. AF.ann. AF.cat.
In the Old Bedford River from Welches Dam to Welney, abundant from Boots Bridge, AF.ann.
New Bedford above Sutton Chain, AF.Flora.
Counterwash Drain, Mepal, Hb ND Simpson, 9.5.1893.
Counter Drain, Mepal and Welches Dam, A Fryer, 1884–95, BM.
Counter Drain, between Mepal and Welches Dam, Alder & Holmes, 1986.
Counter Drain, Welches Dam, 471.859, with P. lucens, CD Preston with Ceri Evans & SD Webster, 27.7.1990, CGE. [not found in CGE]
Welches Dam, not found, CJ Cadbury et al, 1993.
The Old Bedford Drain, Mepal, CR Billups, 4.9.1886, det Dandy, CGE.
Fen drain, Mepal, EW Hunnybun, 14.8.1906, det. Dandy & Taylor, CGE.
Dyke near Fortey's Hall Fen, Mepal, E Knowling & E Vachell, 30.7.1933, det. Dr Taylor, NMW.
Dyke, Langwood Fen nr Mepal, R Melville, 5.6.1938, det CD Preston 1987, K.
Forty Foot Drain near the Three Pots, 42–87–, SM Walters et al, 1952.
Vermuydens Drain by the Three Pots, 42–.87–, SM Walters, JSL Gilmour, PD Sell & C West, 18.9.1952.
Counter Drain between Block Fen & Welches Dam, MPB Grose & DS Allen, 1978, Nat. in Cambs 23:30.
Block Fen, Welches Dam, Counter Drain river, freq. at 3 sites, 46–84–, MPB Grose & DS Allen, 1978;1979. 49
Sixteen Foot Drain, Bedlam Bridge, 46–94–, SM Walters, 1954.
Wimblington Gravel Pits, 43.91, SM Walters, 1966. 56
Burwell Fen, JE Lousley, 1881–3, BM. SLBI. (Bennett,1899).
Burwell Fen. Bennett,1899,246.
Lode, CEM ann.
Reach Lode, A Fryer, 1894, BM,.
Reche load, Hb JA Power, 10.6.1835, RTE.
Reach Lode EA George, 1940.
Reach Lode AO Chater, 1955.
On lode, east of road, Waterbeach Fen, at end, PH Oswald, 11.6.1952.
One patch, Wicken Fen, 545.696, CD Preston & J Fant, 13.7.1996, [R]. 57
R.Cam, Upware, FA Hanbury, 1863, BM.
South Pit Upware, CEM ann.
Upper R. Cam, floating free, [no grid ref.] DJ Griffiths, 20.7.1952, det Dandy, CGE.
By Sandy's Cut. Newbould. Bab.1860,249 & Bab.MS.Fl.3:785.
Wicken Lode, A Fryer, 28.6.1887, BM.
Wicken Cut, AF.ann.
Wicken Lode, CEM ann.
Wicken Lode, E.C.Wallace, 1934, OXF.
var brevifolius Celak.Wicken Lode, EC Wallace, BEC Rep. 1934.
Wicken Fen, HW Pugsley, 1935, BM.
Wicken Fen, n.c., 1937, det Dandy, CGE.
Wicken Lode, 56–70–, NF Stewart, 1.8.1992, [R].
On S side of Wicken Lode, immediately E of junction with Monk's Lode, 560.701, CD Preston 93/88, & Miss SE Yates, 26.12.1993, CGE. [spec. not found.]
Near north end of Wicken Lode, 562.704, and Wicken Lode, 560.702, CD Preston, 1.7.1995.
Luxouriant in deep water and locally frequent from here to Monk's Lode, Wicken Lode, 56–70–, CD Preston & J Fant, 13.7.1996, [R].
R. Great Ouse, Ely, 54–78–, and Stretham, 52–73–, AO Chater, 1955.
Old West River W of Fish & Duck, FH Perring, 25.7.1965, det. SM Walters.
Between Burwell and Fordham, A Bennett, 1883. Bennett,1899,246. 58
Went is class to Ely by the rail. Mr. W. Marshall met us, conducted us by the lane to the outlet of Rossall Pits. There we obtained a barge and navigated the pits in all directions, finding many interesting aquatic plants. Potamogeton praelongus was growing in the pit in small quantity. Bab.Mem.31.5.1854 172.
Roswell Pits, Ely, CC Babington, 31.5.1854, det. Dandy & Taylor, CGE.
Roswell Pits, Ely. Bab.1860 249 & Bab.MS.Fl.3:785.
Roslyn Pits, RI Lynch, & W Hillhouse, 18.6.1880, CUBG 84/80.
Roswell Pits Ely, A Malins Smith, before 1905.
Crooked Drain near Ely, H & J Groves, 2.6.1884, as P. x zizii, det Dandy & Taylor, CGE.
Crooked Drain near Ely, H.& J.Groves, 1884, BM.
Ely Docks, A Fryer, 1883, BM.
Docks by the railway, AF.Flora.
Ely, AF.cat.
R. Great Ouse, Ely, RS Adamson, 1912, det Dandy & Taylor, BM. ?58
Lode, Ely Cut E 25, AC Trueblood, 1940. 20
Stone Corner Bridge, 27–00–, Thorney, 28–04– and Grange Farm, 29–08–, AO Chater, 9.7.1955. 30
Parson Drove, 37–08–, AO Chater, 6.7.1955.
Malice Farm, 30–08–, AO Chater, 9.7.1955. 40
Ring's End, 40–02–, and near Coldham Station, March, AO Chater, 6.7.1955.
