IN ASCENDING REGIONS. 65 



yet form part of the open sward. Epilobium alpinum is 

 more strictly a median species. Betula nana also occurs 

 here, nor have I met with it lower down. Arabis petraea 

 is sometimes seen. Perhaps the best characteristic of this 

 region is the absence at once of Pteris aquilina, which 

 rises to the extreme limit of the uplands, and of Salix 

 herbacea and Azalea procumbens, often descending low 

 down in the subalpine region. Several species will (for 

 the present) be considered to cease here, which certainly 

 rise above the uplands, and possibly even to the subalps ; 

 such as Geranium sylvaticum and Senecio Jacobaea. 

 Genista anglica and Cytisus scoparius I have not seen in 

 England above the upland region ; indeed they are usually 

 surpassed by the Ulex europaeus in England and south of 

 Scotland, although far exceeding this latter shrub in 

 Aberdeenshire ; and the Genista I have observed growing 

 on a level with Carex rigida and Gnaphalium supinum. 

 Rubus Chamaemorus and Cornus suecica begin to prevail 

 here, and though a few very low stations are given for 

 them (as the Hole of Horcum, in Yorkshire, for the latter ; 

 Cleghorn andBoniton woods, Lanarkshire, for the former), 

 it is in the present, and lower part of the next region, that 

 they appear to find their most congenial climate. Juncus 

 triglumis and Tofieldia palustris are of increased frequency. 

 Linnaea borealis forsakes the shade of the forest for the 

 partial shelter of the heath-clad moor; and Trientalis 

 europsea is often seen on the open commons or sheep pas- 

 tures. The interposition of this narrow and somewhat 

 ambiguous stage enables us to draw a more decided 

 distinction between the Low and High Grounds, or 

 Mountains ; a distinction founded in nature, for the true 

 alpine and subalpine species (Gnaphalium supinum, Jun- 

 cus trifidus, Saxifraga nivalis, &c), occasionally trespass- 

 ing into this region, are never found below it. 



