428 POLYGONACEAE 



A form with very large leaves occurred near Grandpont on waste 

 ground. 



P. Persicaria occurs in all the bordering counties. 



P. maculatum, Trim. & Dyei*, Journ. Bot. ix. (1871) 36, or Krock, Fl. 



Siles. Suppl. ii. 72 (Index Kewensis). 

 Polygonum pensijlvap.icum^ var. caule maculato, Curtis, Fl. Lond. fasc. i. 



t. 25. Polygonum nodosum, Bab. Man. Brit. Bot. ed. 6. P. laxum, E. B. 



Suppl. t. 2822. P. lapathifolium, var. maculatum, Sibth. Fl. Oxf. 129. 

 Top. Bot. 354. Reichb. Ic. PI. Crit. v. 56. Fl. Oxf. 256. Nyman, 637. 

 Native. Agrestal, paludal. River-banks, newly turned up mud on 



ditch and stream-banks, waste ground. Locally common, more 



frequent in low-lying districts. A. July-September. 

 First record. Sunninghill, Sir Joseph Banks \_it]^'], in Herb. Brit. Mus. 



1. Isis. Wytham. 



2. Ock. Near Ferry Hinksey. Kennington. Sandford. Near 



Abingdon. Shippon, Grandpont. Radley. Cothill. Osney, 

 the author in Rep. of Bot. Rec. Club, 1884. 



3. Pang. Tilehurst. Tidmarsh, Tufnail. Moulsford. 



4. Kennet. Aldermaston. Mortimer. Benham. Southcote. 



5. Loddon. Sunninghill (/. gracile, teste Trimen & Dyer, 1. c.^, Banks. 



Coleman's Moor. Whistley Green. Windsor Park. Knowl Hill. 



I have kept this as a distinct species, but I am by no means clear 

 that it deserves that status. The size of the nuts, howevei*, appears to 

 be constantly smaller than in P. lapathifolium. The form densum as 

 well as gracile is found. 



P. maculatum occurs in all the bordering counties. 



P. amphibium, Linn. Sp. PI. 361 (1753). 



Top. Bot. 354. Synie, E. B. viii. 77, t. 1241-2. Nyman, 637. Fl. Oxf. 256. 

 Native. Lucustral. Ponds, rivers, ditches, damp fields, and stream- 

 sides. Frequent and widely distributed, and a conspicuous feature 

 in the Thames vegetation. P. July-September. 

 First record. St. Dunstan's Green the terrestrial, and Sonning the 

 aquatic form, Mr. S. Rudge, in Herb. Brit. Mus. 1800. Included in 

 Russell's Cat. 1839. 

 The aquatic form, Syme, E. B. t. 1242, is common in all our larger 

 streams and in ornamental sheets of water, such as Bviscot, Buckland. 

 Lockinge, Radley, Didcot, Uffington, Aldermaston, Hampstead Mar- 

 shall, Marsh Benham, Southcote, Wargrave, J. C. Melvill ; Ruscombe, 

 Binfield, Bulmarsh, Bearwood, White Knights', Easthampstead, Wel- 

 lington, Sandhurst, Sunninghill, Virginia Water, Windsor Park, 

 Frogmore, &c. 



The terrestrial plant, which is often in a flowerless condition, is the 

 form var. terrestre, Koch, Syn. Fl. Germ. 617, Syme, E. B. t. 1241, 



