THE r>RITI,SIl AND SWISS ALPINE FLORAS. 
53 
The distribution of Ihitisli alpines, especially in the typical area of 
the Scotch Ilighlands, has not been worked out as fully as might be. At 
present we know little as to the extreme and average limits to which oui- 
alpine species descend. Until these details are forthcoming it will not 
be possible to summarise accurately the extent of our ]>ritish alpine and 
sub- alpine flora. In the present state of our knowledge, we may roughly 
estimate the British alpine flora at about ninety species, of which nearly 
thirty are confined to elevations above 2,500 ft. The genera Saxifraga, 
Hieracium, Salix, Juncus, and Carex have the largest number of alpine 
species. The sub- alpine zone in Britain is ill-defined, owing to the short 
range of elevation. There are some twenty-five to thirty species which 
may belong to this zone. Some of these are extremely local, such as 
Phyllodocc ccerulea, Bab., only found on the Sow of Atholl, Perthshire. 
One sub-alpine Saxifrage, *S'. Geum, L., as also the Alpine Saxifraga 
umbrosa, L., London Pride, is confined to Ireland. 
Many lowland plants ascend to considerable elevations in the moun- 
tains of Scotland, the Lake District, and North Wales, just as we saw to 
be the case in the Alps. Hooker, in his " British Flora," mentions 
seven lowland species which ascend to 4,000 ft. These are : — 
Ranunculus acris, L. Achillea millefolium, L. 
Viola palustris, L. Rumex Acetosa, L. 
Oxalis acetosella, L. Festuca ovina, L. 
Empetrum nigrum, L. 
There are also at least 120 species which ascend to 2,000 ft., and nearly 
fifty which reach 3,000 ft. These, together with the alpines given below, 
make up the phanerogamic flora of our mountains at heights above 
2,000 ft. 
The following tables give the chief alpine and sub-alpine species in 
Britain. In both cases, especially the sub-alpine, the enumeration is 
probably not complete, and in the latter a few of those included are 
perhaps not really sub-alpine, much work being still needed as to the 
limits of the distribution of these species. 
The great majority of the species which are alpine or sub-alpine in 
Britain occur also in Switzerland, and generally at corresponding altitudes. 
Such species are marked * in Tables I.-III. Here, again, we have further 
proof of the close consanguinity which exists between these two floras. 
TABLE I. 
Beitish Alpines. 
Not descending below 2,500 ft. 
*Arabis alpina, L. *Astragalus alpinus, L. 
Draba rupestris, Br. *Potentilla salisburgensis, Haenke 
*Cerastium trigynum, Villars Saxifraga rivularis, L. 
*Arenaria Cherleri, Benth. * cernua, L. 
„ hirta, ^Yormsk. caespitosa, L. 
