Hart— the Mountain Flora of Ireland. 559 
I^'evertlieless, as I have already observed, it is interesting to find 
some Scotch Alpine species less Alpine in Ireland ; and it is to be 
remarked that the difference in latitude enhances this discrepancy. 
According to Watson's Cyhele Britannica — 
Saxifraga nivalis has 2100 feet for lower limit in Scotland. In 
Ireland it descends to 1950 feet in Sligo. 
Salix herlacea has 1860 feet for its lower limit in Scotland 
(Dr. Dickie, however, reports it at 1600 feet in Orkneys). 
In Donegal it descends to 800 feet in one place in Innish- 
owen, and abundantly to 1000 feet in Fanet and elswhere. 
Silene acaulis and Dryas odopetala descend, the former to less 
than 600 feet above the sea in Donegal, and the latter to 
sea-level in Clare and Galway. These do not reach sea-level 
in Great Britain till we come to the Orkneys and Shetlands. 
Saussurea alpina and Carex rigida both descend to 1000 feet 
in Donegal. We shall have to travel probably far north in 
Scotland before we meet them so far down the mountains. 
I have not been able to find out accurately in what part of 
Scotland this may occur, but not, I think, south of lat. 57°. 
Thalictrum alpinum^ Aralis petrcea, Draba incana^ Saussurea 
alpinttj Arctostaphyllos uva-ursi, Oxyria reniformis, Poly- 
gonum viviparum, Foa alpina, Polystichum lonchitis^ Carex 
rigida^ and Isoetes laeustris find their most southern habitats 
in the British Islands in Ireland. With the exception of 
Arahis petrcea and Arctostaphyllos uva-ursi, these occur in 
Kerry. Of the latter two, the first occurs in Tipperary, the 
latter in Clare. 
This is of interest, since the Brecknock Beacon (2910 feet) in 
Wales is higher than any mountain in its latitude, or south of it, in 
Ireland. Brecknock Beacon is a little north of Hungry Hill (2248 ft.) 
in Cork, which is the most southern point containing any Alpines in 
Ireland. Of these Carex rigida and, I think, Isoetes laeustris are not 
found south of the Irish stations in Europe. 
The late Mr. Watson, in his standard work, the Cylele Britannica^ 
adopted two primary divisions, into which the plants of Great Britain, 
under the joint infiuence of latitude and elevation, arranged them- 
selves. Each of these divisions he further subdivides into three 
zones. The primary divisions he names Arctic and agrarian, and the 
