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 {Bestandetypas) of Nardus stricta in the Puschlav 

 region of the Swiss Alps. This Alpine Nardetum is found at 

 much higher altitudes than occur anjrvvhere 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 : 30.5 — 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 



Vacciniuni 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 



