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. 
Vaccinium-moor. 
‘’ Summit-heath. Eriophorum-moor. Sphagnum-bog. 
s Heather-moor Erica Tetralix-moor. 
3 | | 
= Calluna-heath. 
in} : ree \ 
> wil \ 
FE _ Grass-heath on-———— Molinia-bog. 
= poor soil 
2 | (Nardus-association). \ 
x | Reed or sedge-bog Myrica-bog. 
| Grass-heath on (Juncus, Carex, etc.). : 
rich soil 2 
| (Festuca-Agrostis 
| association). Marsh? 
> 
Increasing moisture. 
