504 
VEGETATION OF BLAKENEY POINT. 
lines. We find these laterals often shew the Suaedas as a broad 
belt with extensive elongated islands of Festuca rubra, together 
forming an interrupted zone in which the Suaedas are either 
absent or small and very occasional. 
The occurrence of F. rubra between the lines of Suaedas on 
the main bank, though in small amount only, may indicate a 
similar origin here as relicts from such a zone. Besides Suaeda 
fruticosa, the other species which are abundant throughout the 
less barren portions of the bank are Arenaria peploides, Sileue 
maritima, Glaucium luteum, and Rumex trigranulatus (Fig. 
16 ) ; of these, the first two are met with throughout the 
length of the bank, not only in the regions of relatively greater 
stability, but also in the older and more mobile parts. 
A renaria peploides probably only tolerates positions in which 
a considerable amount of sand is present, a condition which 
obtains along the greater part of the Blakeney bank ; generally 
speaking, Arenaria approaches nearer the sea than any of the 
other plants of this formation, not infrequently being found 
some way down the seaward slope. Silene maritima, like 
Arenaria peploides, is not by any means uncommon on the 
neighbouring dunes, and the presence of these two species here 
shews that they can endure considerable mobility, which is in 
harmony with their moderate abundance on the older parts 
where other species are either very rare or entirely absent. 
These two plants, with their extensive aerial systems and deep 
roots, can be regarded as the “ Psammas of the shingle,” and 
this is especially true of Silene maritima. 
The densest vegetation, as perhaps we should expect, is to be 
found where the Suaeda bushes are most numerous on the crest. 
In general, as has been pointed out by Prof. Oliver (loc. cit.), 
the barren or almost barren stretches are those where, 
owing to the absence of fringing marshes, .the bank is unfed by 
accumulations of drift. But the amount of vegetation where 
there are bordering marshes is far from being constant through- 
out, and in fact corresponds broadly to the extent of surface 
stability brought about by the groyne action of the Suaeda 
