114 VEGETATION OF THE PEAK DISTRICT [CH. 



(2) Molinia Grassland 



The wetter type of siliceous grassland (cf. p. 106), dominated 

 by the purple moor-grass (Molinia caerulea), is of far less extent 

 in this district than the Nardus grassland, and much more local 

 in its occurrence. 



The Molinia grassland occurs, as a rule, on flatter ground than 

 the Nardus grassland (cf. figure 14). In a very general way, the 

 Molinia grassland affects the ground overlying the sandstone 

 rocks and the Nardus grassland the steep slopes of the shales. 

 Occasionally, the Molinia grassland occurs on shales where the 

 drainage is obstructed by boulders which have fallen from an 

 escarpment of sandstone. Invariably, the soil of the Molinia 

 grassland is wet, often very wet, and more or less peaty. Such 

 soil is, in this district, always acidic; but Molinia is by no 

 means always confined to acidic soils. In East Anglia, for 

 example, Molinia occurs on alkaline peaty soils ; and here the 

 associated species are different from those of acidic soils. On 

 acidic soils, the Molinia grassland is transitional between grass- 

 land and moorland, as was recognised by R. Smith (1900 b : 

 454) ; and examples occur which might quite fairly be placed 

 among the moorland associations. The moorland character is 

 seen in its acidic peaty soil, often supersaturated with moisture, 

 and in the abundance of associated species which characterize 

 certain parts of the moorland. Some of the Molinia associa- 

 tions of this district are almost demonstrably derived from 

 oak or birch woods with a heathy ground flora; and there 

 can be little doubt that it sometimes develops into moorland. 

 Transitions of this nature occur on the south side of Longden- 

 dale, near Crowden railway station. In a few cases, perhaps, 

 Molinia invades the Nardus grassland ; and Molinia is frequently 

 an associate in the heather moor. 



The plant (Molinia caerulea) has a wide range of form and 

 habitat. The variety of form known as Molinia caerulea var. 

 depauperata, with one-flowered spikelets and shorter leaves and 

 shoots, occurs in very wet places. Usually, the plant (Molinia 

 caerulea) is about half a metre high ; but here and there a 

 variety (M. caerulea var. major) with wide -spreading branches 

 of the inflorescence occurs. The plant is deserving of a careful 



