Grass heath Association 95 



commonly dominated by the so-called "heath grasses," 

 i.e. those inhabiting sandy soil. The tracts of country 

 occupied by this association are often called " heaths V' 

 although the true heath plants (Galluna, Erica, etc.) may 

 be entirely lacking, but all transitions are found between 

 the grass heaths and the Calluna-heajths. It seems prob- 

 able that the difference is determined in the first place by 

 the amount of lime and other soluble salts in the sandy soU. 



The association is characterised by a great number 

 of dicotyledons, very largely annual, and often early 

 flowering ephemeral species. Sometimes indeed these 

 are so numerous that the grasses cannot be said to be 

 dominant at all. Many of these species are central 

 European forms which in this country are confined to 

 south-eastern England. 



On very dry grass heaths no close turf is formed and 

 much open soil is exposed. Such places are frequently 

 invaded by weeds from neighbouring sandy arable land. 



The following is a list of species occurring in the 

 grass heath association:— 



1 This term is even used in East Anglia for tracts of chalk pasture, 

 e.g. Boyston Heath, Newmarket Heath. 



