256 



BRITISH PLANTS 



ing way. Variations due chiefly to altitude are indicated 

 vertically; to moisture, horizontally; the wet types to 

 the right, the dry to the left. 



IS 



Summit-heath. 



Heather-moor— 



I 

 Calluna-heath. 



Vaccminm-moor, 



Eriophorum-moor. Sphagnum bog. 



-Erica Tetralix-moor, 



Grass-heath on 



poor soil 

 (Nardus-association), 



Grass-heath on 



rich sou 

 (Festuca-Agrostis 



association). 



-Molinia-bog. 



Eeed or sedge-bog 

 (Juncus, Carex, etc.). 



Myrica-bog. 



Marsh. 



Increasing moisture. 



