POLYGONUM 427 



Native. Agrestal. A weed in cultivated ground, damp waste places, 

 manure-heaps, &c. Especially abundant in turnip and mangold 

 crops and by river-banks on dredged mud. Common and widely 

 distributed. A. June-October. 

 !First record. Sunninghill, Sir Joseph Banks, in Herb. Brit Mus. 1773. 

 Included in Russell's Cat. 1839. 

 Normally the flowers are of a greenish white, but occasionally it is 

 found as vai\ rttbrum (Gray, Nat. Arr. ii. 27o\ in which the perianths 

 are red, as at Hinksey, Abingdon, Tidmarsh, near Eeading, Mor- 

 timer, &c. 



Var. INCANUM, Gren. et Godr. Fl. Fr. iii. 47 = P. incanum, F. W. 

 Schmidt, Fl. Boem. iv. 90, occurs notunfrequently on waste ground, as 

 at Ferry Hinksey, Abingdon, Tilehurst, Windsor, &c. 



P. LAPATHiFOLiuM X Persicaria. Plants are occasionally found 

 having characters which are intermediate between P. lapathifoUum and 

 P. Persicaria. They are possibly hybrids. Mr. Tufnail tells me he 

 noticed very intermediate forms at Mortimer. 



P. lapathifoUum occurs in all the bordering counties. 



P. Persicaria, Linn. Sp. PI. 361 (1753). Spotted Snakeweed. 



Persicaria maculosa, Gerard, 361. 

 Top. Bot. 355. Syme, E. B. viii. 74, tt. 1237-8. Nyman, 637. Fl. Oxf. 257. 

 Native. Paludal, &c. Wet places, ditches, cultivated ground, marshes, 

 waste places, &c. Found abundantly in all the districts, but less 

 frequently in the uplands. June-October. 

 First record. Sunninghill, Sir Joseph Banks, 1773. Sonning, Mr. S. 

 Ruclge, in Herb. Brit. 3Ius. 1800. P. Persicaria, Spotted Snakeweed, 

 Mavor's Agr. Berks, 1809. 



P. Persicaria is a very variable plant. The flowers, which are normally 

 dark pink, are found occasionally white, pale pink, or crimson. Speci- 

 mens are also found which have a few glands on the perianth. When 

 growing on goose-greens, where the plant is much bitten off, it 

 assumes something of the appearance of P. minus. 



Var. INCANUM, Gren. et Godr. Fl. Fr. iii. 48, is rather frequent on 

 places where water has stagnated, and by river-sides. It occurs in all 

 the districts. 



Var. ELATUM, Gren. et Godr. 1. c. =P. biforme, Wahl. Fl. Suec. i. 242, is 

 a luxuriant shade form with brighter green, narrower leaves, and with 

 stalked lateral spikes which are less divaricate than in the typical 

 form. The peduncles are larger and more slender. It occurs with 

 white and with red flowers. It has been noticed at Kennington, 

 Abingdon, Aldermaston, Ruscombe, &c. 



Var. PROSTRATUM, Brebisson, Fl. de la Normandie, 271, with de- 

 cumbent stems, lanceolate leaves, marked with black above and white 

 below, with short spikes, occurs on river-banks, as near Ifiley, &c. 



