Floristic Composition of Limestone Grassland 159 



heath may be produced. A limestone or calcareous heath 

 is characterised by the occurrence side by side, on soils 

 unmixed with non-calcareous debris, of calcicole plants 

 and calcifuge plants. The former are, in the majority 

 of cases, deep tap-rooted plants ; and the roots reach down 

 to the lower layers of soil where the lime-content is high. 

 The latter are nearly always plants with a superficial 

 root-system whose activities are confined to the leached ' 

 upper layers where the lime-content is low. Thus, such 

 calcifuge plants as Calluna vulgaris may be found grow- 

 ing side by side and completely mixed up with such lime- 

 loving plants as Poterium Sanguisorba^. 



The following is a list of plants occurring in the 

 limestone grassland association of the Pennines. 



Moss, 1907 and 19H. 



