40 VEGETATION OF BLAKENEY POINT. 



of very small extent, and forms an excrescence on the side of 

 the main bank some one-and-a-third miles from its distal 

 termination at the Lifeboat House; this, like the "Long Hills," 

 is also a late phase, and is designated by the name of " The 

 Hood." 



The Blakeney dunes, although they do not furnish us with 

 any of the final stages in sand fixation, are of great interest as 

 affording a striking series from the first small heap of sand 

 collecting around a single plant of Marram grass to the semi- 

 fixed condition on which numerous species compete with one 

 another. 



(a) The Headland. 



The main system comprises several parallel series, which 

 increase in height as we pass away from the sea front, and 

 finally reach a maximum as a more or less continuous ridge 

 (the Beacon Hills), whence the general slope is at first some- 

 what steep, followed by a gradual fall to the margin of the 

 Pelvetia Marsh, thus forming a more flattened and relatively 

 sheltered expanse on the leeward face (Fig. 7). A search on 

 the flat beach, where the youngest stages are in progress of 

 development (Cf., Fig. 14), reveals Psamma seedlings about 

 which the sand has only just begun to collect in miniature 

 kite-shaped heaps, the long tapering tails of which swing to and 

 fro with each change in the direction of the stronger winds. 

 Even the most advanced in this first series are not more than 

 one or two feet in height, and support a flora which consists 

 exclusively of Psamma. The outward edge marks the limit of 

 normal tide action, and in consequence a region of drift 

 accumulation. 10 It is here that we find in the greatest abundance 

 plants characteristic of dune faces, such as Cakile maritima 

 and Salsola Kali; here, too, where sand meets shingle, Arenaria 

 peploides and Atriplex hastata are frequent, the former some- 

 times acting as a sand collector and producing sand hummocks, 

 but which unless colonised by the Marram grass do not reach 

 any further stage. 



15. The central figure in Fig. 14, is standing on the drift line beside an inlet of 

 the sea between the ranges of young dunes. 



