526 
VEGETATION OF BLAKENEY POINT. 
reflected in the abundance of ephemeral plants on the older 
phases in the early part of the year, which pass through their 
life history in those few months in which the rainfall is greatest. 
In the late autumn and spring these plants form an almost 
continuous carpet, but by July they have nearly all shed their 
seeds and become so dried up as to leave little evidence of 
their former dominance. Chief amongst the ephemerals are 
Cerastium tetrandrum, Erophila vulgaris, Cerastium semi- 
decandrum, and Stellaria Borceana ; whilst scarcely less 
abundant are Phleum arenarium and Myosotis collina, all of 
which probably play an important part in surface protection 
during a critical period of the year. Where there are depressions, 
such as local subsidences due to rabbit holes, in which the soil 
remains damp even in summer, ephemerals may still be found 
in the later months, particularly Stellaria Borceana, but such 
exceptions merely emphasise the dependence of these shallow- 
rooted plants on surface moisture. 
The Sand-Binders. 
The sand-binder par excellence is of course the Marram 
grass, which furnishes the skeletal structure of the system but 
does little to fix the actual surface itself. The latter function 
is to a large extent performed by Festuca arenaria, which 
comes in at an early stage, and locally we also find the sand 
sedge ( Carex arenaria) , but always in situations of comparative 
shelter, as though climatic conditions were an important factor 
in its distribution. 
The sea convolvulus, which elsewhere plays a conspicuous 
part in the fixation of sand, is on our area confined to a single 
flat-topped dune on the lee side of the main ridge. In this one 
spot it is the most abundant plant, and associated with it are 
Senecio J acobcea { c), Anagallis arvensis (c), Cerastium semi- 
decandrum (c), Erodium cicutarium (f.c.), Psamma arenaria 
(f.c.), and Silene maritima (r.r.) 
The following list is compiled from the dunes of the Head- 
land, and fairly represents the flora in this phase. The only 
species which calls for special remark is Elymus, represented 
