CHAPTER V 



THE PLANT-FORMATION OF THE OLDER SILICEOUS SOILS 



A. The Pennine Ebgion 

 By C. B. Moss 



The older siliceous soils, alluded to in this chapter for 

 the sake of brevity and convenience simply as siliceous 

 soils, include the soils of the metamorphic and Paleozoic 

 non-calcareous rocks, such as schists, slates, sandstones, 

 and shales, but not the sandy soils derived from the more 

 recent rocks, such as the Triassic sandstones, the Upper 

 and Lower G-reensand, the Eocene sands, and the glacial 

 sands. The plant-formation of the latter sandy soils is 

 treated in Chapter III. 



Siliceous soils are usually much shallower than sandy 

 soils : they contain less silica : they are frequently more 

 finely grained in texture : when wet they are much more 

 greasy or slippery; and, at the surface, they often de- 

 generate into a kind of false clay. Siliceous soils, when 

 well aerated, are characterised by the presence of "mild 

 humus " : when badly aerated, damp or wet, acid peat 

 tends to accumulate on them. Sandy soils, on the other 

 hand, often give rise to the drier, though still acid, peat 

 or humus which is characteristic of typical heaths (see 

 Chapter IV). 



These differences, perhaps along with others not yet 

 fully understood or appreciated, between siliceous and 



