Groenlandia densa (L.)Fourr. (Potamogeton densus L.)
First record: Ray, 1660
Tribulus aquatic minor muscatellae floribus Small Frogs Lettuce or water Caltrops. In rivers. Ray,1660,165(118).
Tribulus aquaticus minor Muscatellae floribus Small Frogs Lettuce, or Water-Caltrops. Ray,1670:301.
Potamogeiton seu Fontinalis media lucens Martyn,1727,16.
Potamogeton densum Dichotomous Pondweed. Relhan,1785; Close-leaved Pond-weed. Relhan,1802;1820.
Ditches. Common, except (?) in the Fens. There are no recorded stations for it in the (7) Chatteris, nor (8) Wisbech Districts. Bab.1860,251.
24
Guilden Morden; WWN. Bab.MS.Fl.3:794.
Tadlow; WWN. Bab.MS.Fl.3:794.
25
Cuxton; WWN. Bab.MS.Fl.3:794.
Gamlingay. Bab.ann.Relhan,68; Bab.MS.Fl.3:794.
29
Whittlesey, The Wash, A Fryer,24.7.1892, det. Dandy & Taylor, BM.
Whittlesey, E of Delph, 269.981, JO Mountford & GMB Smith, 17.6.1972; JO Mountford, 16.7.1975 & 13.2.1984; Whittlesey Common Wash, 268.982, ditch east side of drove at east end, frequent, G Crompton & R Payne, 5.7.1988; (first seen here, R Payne c. 1980).
Whittlesey Nene Wash, 285.992, plentiful in southern half of drain leading from sheds on Long Drove to Morton's Leam, R Payne, 24.8.1988.
S of Long Drove, Nene Washes, 283.992, small quantity in ditch, CD Preston et al., 17.8.1991.
Whittlesey Washes, 29U, ditch on W of track from car park, CD Preston, S Lambert et al., 1.8.1993, [R]; 29Z, T Pankhurst et al., 9.8.2002, [R].
Pumphouse drain to W of Must Farm, Whittlesey, M Palmer, 14.6.1994, [R].
Yardy's Pit, 25-98-, NP Millar, 21.8.1997, [R].
33
Melbourn Common. Bab.MS.Fl.3:794.
35
Bourn; WWN. Bab.MS.Fl.3:794.
Gravel pit between Caxton & Eltisley; WWN. Bab.MS.Fl.3:794.
Gt Eversden; WWN. Bab.MS.Fl.3:794; Bourn Brook due S of Toft Manor, 362.553, RGH Cant, 1997, [R].
Old North Rd. Golden Lion Inn, WP Hiern, 31.5.1864, det. Dandy & Taylor, RAMM.
Wimpole Avenue; WWN.! Bab.MS.Fl.3:794.
36
Near Birds Pastures; WWN. Bab.MS.Fl.3:794.
Elsworth; WWN. Bab.MS.Fl.3:794.
Swavesey, 360.708, JO Mountford, 1988, [R].
In brook near Bridge in Cuckoo-lane. [by Westwick field]. Bab.MS.Fl.3:794.
37
The Cranbrook, AF.Flora.
Overcote Fen, drain SE of Chain Ditch, 364.709, very common, in middle area of Drain with Hottonia, JO Mountford, 3.9.1986; still present, with Elodea nuttallii, JO Mountford, & A Zemmelink, 13.8.1989.
Ouse near Swavesey. Bab.MS.Fl.3:794; Swavesey R. Ouse Counter Drain, 360.708, large patch, JO Mountford, 31.8.1988; not found, but much Hydrocharis present, JO Mountford, 1989.
38
Chatteris, Crooked Drain, Old Halves, AF.Flora.
Faerys Meadlands, Farm, Sutton, A Fryer, 31.8.1888, det. Dandy & Taylor, BM.
44
Ickleton. Bab.MS.Fl.3:794.
Triplow, Hb. CC Babington, 17.7.1860, det. Dandy & Taylor, HAMU.
Specimen: Potamogeton densus ...from the old Lodge Moat Alderbury Whittlesford and beside Wipperty 1867. Maynard MS.13:425.CRO.
45
Cambridge, EA Holmes, 5.1832, det. Dandy & Taylor, BM; Rev R Blunt, 5.1832, det. Dandy & Taylor, K; HE Lowe, 5.1833, 6.1836, det. Dandy & Taylor, WARMS; Cambridge, Bab.ann.Relhan,68; Bab.MS.Fl.3:794; Cambridge, RJ Pankhurst, 10.7.1970.
River Cam, [?Cambridge] RH Lock, 30.5.1901, det. Dandy & Taylor, CGE.
Near Cambridge, CE Moss, 10.5.1914, det. Dandy & Taylor, CGE. not found.
Barnwell West NR, 47-58-, SM Walters & K Walters, 11.6.2001, [R].
Coe Fen, n.c., 20.6.1899, det. Dandy, CGE.
Romsey Town, 476.575, GMS Easy, 1980; Cherry Hinton Brook, 476.573, CD Preston, 11.8.1985; along the street called Burnside, Romsey Town, 475.574, CD Preston 87/1, 11.1.1987, (same site as CDP, 11.8.1985), CGE.
Coldham's Common, DM Griffin & DJ Griffiths, 17.8.1952, det. Dandy, CGE; Coldham's Common, 47-58-, ME Smith, CJ Cadbury et al., 18.7.1980, [R]; 477.583, GMS Easy, 1980; Abundant in shallow chalk stream, with Ranunculus trichophyllus, Sagittaria, Coldham's Brook, Coldham's Common, 478.586, CD Preston, 28.6.1987, CGE.
Shallow chalk stream (almost a ditch), Coldham's Brook, in front of the allotments, Coldham's Common, 471.590, with Ranunculus trichophyllus & Sagittaria, CD Preston, & Q Cronk 8.7.1987, (Spec. drawn by J Ellis for BSBI Handbook). CGE; 472.591, scattered over at least 100m of ditch but nowhere common, CD Preston & NF Stewart, 23.3.1997, [R]; 47-58-, NF Stewart & T Pankhurst, 4.6.1998, [R].
Several patches in clear shallow running water, watercourse running parallel to but above and to W of Coldham's Brook, E end of Coldham's Common, 4785.5855, AC Leslie, 18.11.2001.
Hobson stream, J Blades ann.Bab; Hodson's Conduit, W.L.P.G., 2.7.1839, SWN.
Queens' College Ditch, 28.6.1949. DE Coombe, Card Index.
Sheeps Green. Bab.MS.Fl.3:794.
Stourbridge, J Killick, 17.8.1958.
Fen Ditton ditch, 477.601-477.599, GMS Easy, 1988.
Harston; WWN. Bab.MS.Fl.3:794.
Hauxton. Bab.MS.Fl.3:794.
Potamogeton densum near Cambridge, [Cambridge-Cherryhinton-Shelford Common] 8.5.1828. Henslow Exc; Potamogeton densum Cambridge to Cherry Hinton and thence to Shelford Common. 14.5.1830. Henslow Exc.
Hinton. Bab.MS.Fl.3:794; Cherry Hinton Brook, TH Cory, 7.1833, det. Dandy & Taylor, BFT; Cherry Hinton, 480.571, GMS Easy, 1980.
Potamogeton densum Shelford J.D., 9.5.1830, NTM.
Shelford Common, WA Leighton, 11.5.1832, det. Dandy & Taylor, CGE.
Hobson's Brook and nearby ditch, Nine Wells, Great Shelford, 459.543, CD Preston, 28.2.1988, CGE; NMW.
Ditch running E from railway line north of Nine Wells, E of Trumpington, (ditch is the Gt Shelford-Trumpington boundary), 459.543, between Gt Shelford & Trumpington, shallow ditch over chalky soil, bordered by arable fields, water clear, c. 25cm deep, CD Preston, 28.2.1988, CGE.
Ditch along E side of railway, near Nine Wells, 459.542, CD Preston, 28.2.1988.
46
R. Cam at Chesterton, AD Melvin, 10.6.1867, det. Dandy & Taylor, BEL; CEM.ann.
Horningsea. Bab.MS.Fl.3:794.
Chear Fen, Cottenham, drainage ditch, 489.699, GMS Easy, 10.9.1980; 10.7.1985, conf. CD Preston 1989, PVT.
Fen Ditton ditch, 477.601-477.599, GMS Easy, 1988.
Waterbeach Fen. Bab.MS.Fl.3:794.
47
Chear Fen, Cottenham, 491.700, drainage ditch, GMS Easy, 10.9.1980; 10.7.1985, conf. CD Preston 1989, PVT.
Chear Fen, S side of R. Great Ouse, 488.714, locally frequent in shallow ditch recently cleared out, CD Preston & N Stewart, 20.5.1989.
Chear Fen, Long Drove ditch, 483.708, CD Preston & S Webster, 22.8.1986.
Chear Fen, Ditch S of Long Drove, 480.709-484.708, small quantity, CD Preston & N Stewart, 20.5.1989.
Chear Fen, 484.708, CD Preston et al., 16.9.1995, [R].
Ditch parallel to R. Ouse, 483.712, E Norman, conf. CD Preston, 26.5.1991.
Cottenham Engine Drain, 480.709, CD Preston & J Fant, 4.6.1996, [R].
Sutton, AF.Flora; 47D, C Turner, 22.9.1991, [R]; Dole Fen, AF.ann; Sutton Meadland, AF.ann; Sutton Wash above Sutton Gault, A Fryer, 8.2.1888, det. Dandy & Taylor, BM.
48
Mepal, AF.cat; Drain SW side of Engine House, Mepal, 441.821-440.820, (just outside Washes), CD Preston, 29.5.1990 in notes to CJ Cadbury, Survey of Ditches.
Near Fortrey's Hall Pumping station, 440.820, small ditch, CD Preston, 1990, 1992, [R]; 440.819, Ditch S of engine house, CJ Cadbury & CD Preston, 31.7.1993, [R].
5m NW of Mepal, 427.832, GMS Easy, 13.9.1975, det. Dandy & Taylor, CGE; PVT.
Sutton Broad Piece, AF.Flora.
Wash ditches below Mepal, CR Billups, 9.5.1893. det. Dandy & Taylor, LTR.
The Washes, AF.ann; of 100ft. AF.Flora.
King's Farm, Welches Dam, A Fryer, 15.7.1883, 20.8.1883, det. Dandy & Taylor, BM; CR Billups, 23.8.1886, det. Dandy & Taylor, LTR; A Fryer, 13.5.1886, 23.5.1888, det. Dandy & Taylor, GL; King's Farm, Welches Dam, A Fryer, 24.4.1888, 5.4.1890, 29.7.1890, det. Dandy & Taylor, BM.
Welches Dam, A Fryer, 22.8.1897, det. Dandy & Taylor, BM; AF.cat; Welch's Dam, Fryer. Bennett,1899,246; Edge of water in small drain near Welches Dam, 467.858, PD Sell, 61/603, 17.8.1961, det. Dandy, CGE; Welches Dam, ditch on far side of Barnes Bank, 467.857, CJ Cadbury, BSBI exc. 6.1973.
Witcham. Bab.MS.Fl.3:794; AF.cat.
Vermuyden's Drain, 1910, CEM.ann.
55
Fulbourn. Bab.MS.Fl.3:794; Near Balsham Road, Fulbourn, WP Hiern, 27.5.1865, det. Dandy & Taylor, RAMM; CGE; N of Fulbourn, W Hillhouse, 19.7.1878, BIRM; Fulbourn, TH Corry, 27.7.1881, 7.1882, det. Dandy & Taylor, BFT; Brook, Fulbourn, 7.1881, A Shrubbs, det. Dandy & Taylor, CGE; Fulbourn, Shardelowe's Wells, EA George, 1940; Fulbourn Fen, GMS Easy, 20.5.1980, conf. CD Preston, 1989, PVT.
Fulbourn, 512.567, A Craig, 5.4.1992, [R].
Quy Water, MH Clifford, 23.5.1935, det. H Gilbert-Carter & EF Warburg as Potamogeton densus x crispus; det. Dandy, CGE.
Abundant in calcareous stream, Quy Water, immediately S of A.1303 bridge, Stow cum Quy, [old Quy/Fen Ditton boundary], 509.594, AC Leslie, 8.1978; CD Preston & G Crompton, 22.6.1989, CGE.
Teversham, AO Chater, 7.1955.
Wilbraham. Bab.MS.Fl.3:794; Temple Wilbraham. Bab.MS.Fl.3:794.
Little Wilbraham River, EF Warburg, c. 1937; Little Wilbraham River & fen ditches adjoining on Teversham & Fulbourn Fens, 30.6.1949. DE Coombe, Card Index.
Wilbraham River, 511.593-522.587, GMS Easy, 1980; Little Wilbraham Fen, SM Walters, 7.8.1954; ditches, 512.592 & 524.595, GMS Easy, 1980.
Ditch between Long Drove and Short Drove and forming northern boundary of Lt Wilbraham Fen, 518.596, G Crompton & CD Preston, 22.6.1989, CGE.
56
Banks of the Cam between Chesterton and Baitsbite. Fens and fields on each side of Bottisham-lode, between the river and Anglesea Abbey. 25.5.1830. Henslow Exc; Bottisham, L.J., 9.6.1823, BATHG; Spring Head, Bottisham. Bab.MS.Fl.3:794.
Bottisham fen. Bab.MS.Fl.3:794; Near Bottisham Lock, WP Hiern, 7.7.1867, det. Dandy & Taylor, RAMM; Bottisham Lode, EA George, 1940; Bottisham Lode, 527.639, PD Sell 50/173, 20.8.1951, det. Dandy, CGE.
Burwell Lode, CEM.ann; Burwell Drove, Burwell Fen, A Bennett, 4.8.1880, det. Dandy & Taylor, BM.
Quy Fen, 4.5.1879, Bent.ann.
Reche load, Hb. JA Power, 7.1835, det. A Bennett, RTE; Reach Lode, N end, EA George, 1940.
Swaffham Prior, n.c., 1828, det. Dandy & Taylor, MANCH; WC Trevelyan, 30.7.1834, det. Dandy & Taylor, NCE; Rev. Jermyn, 7.1836, det. Dandy & Taylor, MANCH; Swaffham Fen H! Bab.MS.Fl.3:794; Swaffham Bulbeck lode, JO Mountford, 9.8.1989, [R].
57
Barraway, CC Babington, 13.7.1860, det. Dandy & Taylor, CGE.
Near Soham, DA Cadbury, 2.9.1948, det. Dandy & Taylor, BM.
Stretham, drain SW of Holt Fen Drove, 52-74-, S Emmerich & L Smailes, 7.7.1994, [R].
Upware, RS Adamson, 21.7.1912, det. Dandy & Taylor, BM; Upware Lock area, SM Walters, 10.7.1954.
Wicken Lode, RS Adamson, 4.6.1908, det. Dandy & Taylor, BM; J Walton, 8.1938, det. Dandy & Taylor, GL; TG Tutin, 3.7.1938, det. Dandy & Taylor, BM; Wicken Lode, near Upware, EA George, 1940; Wicken Lode, JO Mountford & GMB Smith, 27.5.1969.
Wicken Fen, CEM.ann; A Lloydell, n.d., det. Dandy & Taylor, OXF; CT Green, 7.1891, det. Dandy & Taylor, LIV; EY Western, 23.6.1900, det. Dandy & Taylor, ?LIV; DM Grifffin & DJ Griffiths, 16.8.1952, det. Dandy & Taylor, CGE; Wicken Fen, Main Lode, G Halliday, 7.1953, det. Dandy & Taylor, LTR.
58
Chettisham Meadows, pond, 541.834, TCE Wells, 14.10.1991; Chettisham New Meadows, Field 8, 540.834, NP Millar, 21.8.1996, [R].
Roswell Pits, Ely. Bab.MS.Fl.3:794.
64
Shudy Camps. Bab.MS.Fl.3:794.
65
Dullingham. Bab.MS.Fl.3:794.
Stetchworth. Bab.MS.Fl.3:794.
W.Wratting. Bab.MS.Fl.3:794.
66
The larger specimen was gathered near Newmarket by Mr Hempsted, ... [ex herb. JR Weatherhead] Hort.Sicc.2:WBCH; Groenlandia densa conf. CD Preston 1993.
Snailwell Fen. Bab.MS.Fl.3:794.
