336 63, POLYGONACEiE. 



Agrarian region. Inferagrarian — Midagrarian zones. 



Descends to the coast level, in Thames province. 



Ascends to 50 or 100 yards, in England. 



Range of mean annual temperature 49 — 48. 



Native. Inundatal, Paludal. A doubtful species, with 

 little to distinguish it from P. Persicaria, except its more 

 slender spikes. The trae distribution cannot be shown at 

 present ; the species, if such it be, being yet unfamiliar to 

 English botanists, and not improbably passed by as a small 

 variety of P. Persicaria, or as a large one of P. minus. 



937. Polygonum Hydropiper, Linn. 



Area 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 * 18. 



South limit in Cornwall, Isle of Wight, Kent. 



North limit in Shetland, Orkney, ? 



Estimate of provinces 18. Estimate of counties 80. 



Latitude 50 — 61. British type of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 100 or 200 yards, in Scotland. 



Range of mean annual temperature 52 — 45. 



Native. Inundatal, Paludal. This common English 

 species apparently becomes quite infrequent in the High- 

 land provinces ; nor am I prepared to adduce a single au- 

 thority for its occurrence in the North Highlands, probable 

 as that may be. It is found, though rarely, in Moray ; I 

 saw it on the shore of Loch Eil, at the west end of the 

 Caledonian Canal ; and Mr. Brand observed it in an inter- 

 mediate locality, by the Lake at Fort Augustus. It is enu- 

 merated by Dr. Gillies as an Orkney plant, on authority of 

 Lowe ; and Edmondston says that it is frequent in Shet- 

 land, It is stated also to reach Faroe ; and is distributed 



