246 POLYGONACE Ai. [Polygonum. 
TI. Abundant in a small bog and in the adjoining swampy 
fields and ditches near the head of the Castlecove stream, 
extending over an area of about twelve acres ; also, at 
intervals, along the stream between this bog and the sea a 
distance of about a mile ; and in a small wet hollow by the 
old road a little to the west of the bog mentioned above : 
R.W.S. 1890, &c.—still in much the same quantity, 1907: 
RWS, 
First found in Ireland in 1889, and recorded in 1890: 
R.W.S., Journ. of Bot., p. 111—as P. arifolium Linn. 
This prickly Polygonum is a native of North America 
where it is found on wet ground over a wide area in the 
United States and Canada, extending from Newfoundand, 
Nova Scotia, and the North-west Territories in the north, 
to Florida and Kansas in the south. Although several Kerry 
localities are given above, they are all obviously derived 
from the swampy hollow in which the plant is very abundant. 
Rough hills rising from 1,000 to 1,785 feet in height almost 
surround this hollow, through which a small stream runs, 
which has carried the plant with it as far as the sea at 
Castlecove, a distance of rather more than a mile. An old 
road which ran from the village of Caherdaniel to Sneem 
crosses this stream just where it leaves the hollow ; this road, 
however, has long since been deserted for the more level 
highway constructed along the coastline and is now reduced 
in parts to little better than a rough foot-track. The 
dwellings which occur in the vicinity are of the poorest 
description. 
It is difficult to account satisfactorily for the presence of 
this American Polygonum in Kerry. That it has been 
introduced here in some way there can be no doubt, the 
difficulty being rather to suggest the means by which the 
plant has come to be so thoroughly established in a small 
secluded bog in this south-west corner of Kerry, the only 
locality apparently known for it in the whole of Europe. 
The late Mr. A. G. More when first shown this plant in 1889 
suggested that it had been accidentally introduced with 
foreign grain. The locality, however, is quite remote from 
the usual sources of alien introduction, such as ports, rail- 
ways, distilleries, &c., while the inhabitants in the neighbour- 
hood are too poor to buy damaged foreign grain for fowl 
feeding, &c., as occasionally occurs in more prosperous 
districts. If introduced in this manner, as seems most 
likely, it is difficult to understand why it has not been 
found in places more favourably situated for the spread of 
