58 



Botany 



carota, Anthyllis vuheraria, Campanula glomerata, Euphrasia officinalis, 

 Thesium humifusum, and Astragalus danicus. Two species of special interest 

 are the Pasque flower [Anemone pulsatilla) and the bee orcliis {Orchis 

 apifera). 



In the above list, the preponderance of hemicryptophytes is particularly 

 striking; it may perhaps reflect on the one hand grazing, on the other, 

 summer drought to wliich the porous chalk soil is very liable. At Royston, 

 there is much local differentiation of grassland types from short rabbit- 

 grazed turf on the hfll crests, with Festuca ovina dominant, to dense thick 

 turf dominated by Bromus erectus, on the deeper soils of the slopes and 

 vaUey bottoms. On disturbed soils, Arrhenatherum auenaceum becomes 

 prominent. 



The general uniformity of the Chalk grassland can be illustrated by 

 comparing with the Royston list those for two separate one-metre 

 quadrats, one on the old Roman road and the other on the Fleam Dyke. 

 Frequencies of the species are given by the conventional symbols. 



" This list is taken from A. G. Tansley, Types of British Vegetation (1911), p. 178. 



