POTAMOGETON 515 



Native. Uliginal. Marshes, wet meadows, &c. Locally common. 



P. June-August. 

 First record. T. palustre. Newbury, Russell's Cat 1839. 



1. Isis. Wytham Meadows. Near Eynsham. Near Coleshill. 



2. Ock. Ferry Hinksey, very fine specimens. South Hinksey. 



Damp fields, near Keunington. Iffley Meadows. Near Sandford. 

 Near Abingdon. Marcham. Kadley. Cothill. Marsh between 

 Wantage and Letcombe. Abingdon Racecourse. 



3. Pang. Tidmarsh, XewboulcL Pangbourn Marsh. Moulsford. 



4. Kennet. Bagnor Marsh, Russell, l. c. Greenham. Newbury. Near 



Theale. 



5. Loddon. Bisham, Cluindler. Wargrave. Sonning Meadows, veiy 



fine, Tafnail. Coleman's Moor. 

 The saline meadow, near Marcham, has a considerable growth of it, 

 hut the mai'itime species does not occur there. I have very few notes 

 of Triglochin from the heathy district, but it is plentiful in the meadows 

 of the Upper Thames. The plant is recorded for all the bordering 

 counties. 



POTAMOGETON", Linn. Gen. n. 160 (Tournefort, Inst. t. 103% 

 P. natans, Linn. Sp. PI. 126 (1753). Floating Pondiceed. 



Top. Bot. 420. Syme, E. B. ix. 26, t. 1399. Nyman, 681. Fl. Oxf. 282. 

 Native. Lacustral. Ponds, rivers, ditches, &c. Common, and gener- 

 ally distributed in all the districts, except over the heathy tracts, 

 where it is replaced by the succeeding species. P. June-July. 

 First record. Bin field, Mr. S. Radge, in Herb. Brit. 2Ius. 1800. P. natans, 

 Mavor's Agr. Berks, 1809. 



P. natans is too common in the Isi^, Ock, Pang, and Kennet districts 

 to need enumeration of its localities. I have found it in Wigmoreash 

 Pond near Gibbet Hill at 912 feet altitude. In the heathy portion of 

 the Kennet district it occurs at Alderniaston, Benham, Stockcross, 

 Hampstead Marshall, and in the Kennet itself, plentifully. In the 

 heathy area of the Loddon district the Rev. C. W. Penny records it for 

 Heath Pool, and it is plentiful in Vix'ginia Water, Bracknell, &c., and 

 abundant in the Thames and Loddon. 



Potamogeton natans occurs in all the bordering counties. 



P. polyg-onifolius, Pourr. in Mem. Acad. Toul. iii. (1788) 325. 



P. oblongus, Viv. Fragm. Fl. Ital. i. i, t. 2. 

 Top. Bot. 421. Syme, E. B. ix. 27, t. 1400. Nyman, 681. Fl. Oxf. 282. 

 Native. Lacustral. Ponds, ditciies, and pools in heathy places. Very 

 rare, or perhaps absent, from the Isis and Ock districts, and very 

 local in the Pang district. Abundant in the heathy part of the 

 Loddon, and locally common in the Kennet district. In the 

 heathy parts replacing P. natans. P. June-August. 



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