178 VEGETATION OF THE PEAK DISTRICT [CH. 
The vegetation of the roadsides, the footpaths, the banks 
of streams, and the fringe of the heather moors is, in general, 
of a grassy nature. In winter, it is possible to distinguish at 
a distance of some miles the sinuous course of old footpaths and 
bridlepaths by the contrast in colour which the bleached haulms 
of the mat-grass (Nardus stricta) make with the surrounding 
dark-coloured moorland vegetation. 
Ostenfeld (1908: 887) states that the heather moors of the 
Faerées are always met with on slopes with a southern exposure : 
this is not the case with regard to this association on the 
Pennines; and the inference is probably to be made that in 
the Faerées, the association of heather moor is near its climatic 
limit of distribution. 
On some of the more lowland of the heather moors, especially 
in sheltered depressions, the bracken (Pieris aquilina) is very 
abundant. It is possible that this plant is extending its range 
on the moors. Wheldon and Wilson (1907: 104) state that on 
the heather moors of North Lancashire, “where grouse are a 
prime consideration, the bracken is mowed periodically at con- 
siderable expense, and the heather is then enabled to overcome 
all rivals.” 
There is not a great deal of human interference with nature 
on the heather moors, although they are systematically fired by 
the keepers every few years. The length of time which elapses 
between the periods of firing varies locally, and determines the 
height to which the heather grows. On Eyam Moor the heather 
is fired about every four years, and therefore does not grow much 
more than ankle high. On the remoter moors in upper Derwent 
Dale, a period of eight to ten years elapses between the periods 
of firing; and the heather, on some of these moors, is frequently 
more than knee deep. For one or two years after the heather 
has been fired, the heather moor presents a desolate appear- 
ance; for the heather does not strongly reassert itself until at 
least two years have elapsed. The first plant to become con- 
spicuous after firing is the bilberry (Vaccinium Myrtillus). The 
latter frequently occurs as a partially etiolated plant under the 
dominant heather, where its habit simulates that of Jistera 
cordata. In such circumstances, however, the bilberry rarely 
flowers or fruits. The underground stems and buds of the 
bilberry are frequently unharmed by the firing, even when the 
