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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