108 VEGETATION OF THE PEAK DISTRICT [CH. 



this district, like it is, for example, on the Malvern Hills or on 

 the Wicklow Hills (cf. Pethybridge and Praeger, 1905: 153, 

 plates 7 and 8); but it occurs in patches in dry and fairly 

 exposed localities. The rush (Juncus effusus and /. effusus forma 

 compactus), in damp places, and independently of conditions of 

 shelter or exposure, is an abundant and characteristic associate. 

 The bracken and the rush, in fact, are, in many places harvested 

 by the upland farmers (see figures 15 and 16). 



The relationships of the various facies and aspects of 

 the Nardus association may be indicated diagrammatically 

 as follows : 



NARDETUM STRICTAE 



I 



Facies of 

 Agrostis vulgaris 



Facies of 



A 



. Deschampsia flexuosa 





Facies of Facies of Facies of S, 



Ulex Oallii Pteris aquilina Juncus effusus 



The bracken facies (see figure 15) and the rush facies 

 (see figure 16) are very well developed in this district. For 

 example, in ascending Longdendale (above Glossop), one meets 

 with Nardus grassland on the hill-slopes. The bracken here 

 varies from being a rare member of the association to a 

 subdominant member. However, the general habitat conditions 

 seem so very constant, and the bracken itself so very variable in 

 amount in different parts of the association (even within quite 

 small areas), that it seems impossible to regard the bracken 

 as modifying the association any more than producing a facies. 

 Towards the head of Longdendale, between Woodhead and 

 Dunford Bridge, the bracken becomes less general ; whilst the 

 rush becomes a normal and an abundant member of the 

 Nardus grassland. Such places are always ill-drained; and 

 from them, the gorse and the bracken are invariably absent. 

 The cotton-grass (Eriophorum angustifolium) sometimes occurs. 

 Such a Juncus facies of siliceous grassland must be distin- 

 guished from the Juncus swamp (Juncetum effusi) described in 

 Chapter VI. 



The bracken is one of the most accommodating of plants as 

 regards its requirements. It is present in nearly all woods, 

 except in the shadiest, dampest, and most calcareous places; 



