CHAPTER VIII 



ALPINE AND ARCTIC FLORAS 



On the summit of a highland mountain, even on 

 moorland hills of no great altitude, there is often a 

 sudden change in the plant world. 



After the exhausted botanist has trudged or bog- 

 trotted through miles of peat-moors and uninterestingly 

 monotonous moorlands, the flora of the weather-beaten 

 summit itself comes as a refreshing change. 



Here there are blackened or mouse-coloured and grey 

 rocks projecting as angular fragments amidst loose dis- 

 coloured pebbles. Their stone surfaces are entirely 

 covered or nearly so by a rich though intricate and diffi- 

 cult series of ugly little lichen-crusts. But all the rocks 

 and stones are framed by a thin nearly continuous moss 

 carpet which stretches over the poor rocky soil, and, so to 

 speak, frames and borders the bolder frost-shattered pro- 

 jections. Here and there, dotted about in this thin mossy 

 covering, one finds a scanty band of the hardiest fore- 

 runners amongst the flowering plants. The "alpines" are 

 the most interesting, for many of them are glacial "relicts" 

 which have been driven to these inaccessible summits 

 by the invading hordes of ordinary lowland plants. 



Such summit floras are of extraordinary interest, for 

 they give many hints as to the first stages in the 

 colonisation of our country after the disappearance of 

 the snowfields and glaciers of the great Ice Age. 



One interesting point about them is that, even when 

 miles away, one can distinguish the " summits " in our 

 sense from the lower and upland hills. The outlines 

 of the ridges and higher ground is generally composed 



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