110 VEGETATION OF THE PEAK DISTRICT [cH. 
related to the siliceous grassland of Britain, as about eighty per 
cent. of the species are common to the two types of vegetation. 
Brockmann-Jerosch (1907: 248, etc.) has described an 
association (Bestandetypus) of Nardus stricta in the Puschlav ~ 
region of the Swiss Alps. This Alpine Nardetum is found at 
much higher altitudes than occur anywhere in England, and 
contains many species which are not indigenous in this country: 
still, about thirty per cent. of the species given by Brockmann 
(1907 : 805—8) are found in the Nardetum of the Peak District 
of Derbyshire; and probably the two associations should be 
placed in the same plant federation (see Moss, 1911), but in 
different geographical plant formations. The elements common 
to the two associations are the following :— 
Botrychium Lunaria Achillaea Millefolium 
Rumex Acetosella Hieracium Pilosella 
Ranunculus acris Anthoxanthum odoratum 
Trifolium repens Deschampsia flexuosa 
T. pratense Sieglingia decumbens 
Vaccinium Vitis-idaea Nardus stricta 
Calluna vulgaris Carex caryophyllea 
Antennaria dioica Luzula campestris 
It has already been emphasised that the woods of the 
district gradually pass into scrub; and similarly the scrub 
imperceptibly passes into grassland. Just as there are many 
localities which are difficult to determine either as woodland or 
scrub, so there are many other places which are difficult to 
determine either as scrub or grassland. Again, whilst much of 
the scrub represents degenerate woodland, much of the grassland 
represents a still later stage of degeneracy than the scrub. 
There can be little doubt that the hill-slopes now characterized 
by grassland were, generally speaking, once wooded; and it is 
highly probable that most of these slopes are capable of being 
successfully re-afforested. In the Nardus grassland on the hill- 
slopes of this district, the following woodland species, among 
others, still linger here and there :— 
Pteris aquilina Betula pubescens 
Nephrodium montanum Lychnis dioica 
N. aristatum Corydalis claviculata 
N. Filix-mas Oxalis Acetosella 
Athyrium Filix-foemina Geranium Robertianum 
Quercus sessiliflora Ilex Aquifolium 
