136 



Plant-formation of Siliceous Soils 



The Molinia pasture occurs in the more badly drained 

 places. In a general way, the Molinia grassland affects 

 the ground overlying the sandstone rocks, whilst the 

 Molinia pasture is more characteristic of the steep slopes 

 of the shales. The soil of the Molinia grassland is wet, 

 often very wet, and more or less peaty and acidic. How- 

 ever, as shown in Chapter X, the purple moor-grass is by 

 no means confined to acidic soils. On such soils, the 

 Molinia association frequently forms a transition from 

 grassland to moorland. The moorland relations of the 

 habitat are seen in the peaty soil (always acidic on 

 siliceous soils), often supersaturated with moisture, and 

 in the abundance of associated species which characterise 

 certain parts of the moorland. 



Molinia is often very abundant in the degenerating 

 oak and birch woods of siliceous soils ; and there can be 

 little, if any, doubt that some parts of the Molinia grass- 

 land have resulted from the degeneration of such woods. 

 Transitional areas occur, for example, near Crowden 

 railway station in north Derbyshire. The following is 

 a list of the species which characterise many of the 

 Molinieta of the Pennines ; — 



