63. POLYGONACE^. 335 



935. Polygonum lapathifolium, Linn. 

 935, b. Polygonum nodosum, Pers. 

 935, c. Polygonum laxum, E. B. S. 



Area 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16. 



South limit in Cornwall, Isle of Wight, Kent. 



North limit in Moray, Aberdeen, Argyle. 



Estimate of provinces 16. Estimate of counties 75. 



Latitude 50 — 58. British type of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 100 or 200 yards, in England. 



Range of mean annual temperature 52 — 47. 



Native. Agrestal, Inundatal, &c. This species may 

 have been seen by myself in the North Highland province ; 

 but the recollection is not sufficiently exact to warrant the 

 addition of that province (17) to the area, or the county of 

 Ross to the north limit of the species. When growing in 

 water it often becomes the P. nodosum. As for the puz- 

 zling P. laxum, while it has little the character of a distinct 

 species, there is still doubt whether it should be received 

 as a form of P. lapathifolium : it is said to have been found 

 in Sussex, Middlesex, Essex, Hereford, and Monmouth. 



^ /^- ^^-f Ji .J-^ 636, Polygonum mite, Schr. 



Area **34*6*^^10. 



South limit in Surrey, 



? ^5rt.^<_-/Sc/»-^ 



North limit in York, ? 



Estimate of provinces — ? Estimate of counties — ? 

 Latitude 51 — 54. English type of distribution. 



