132 IJR. J. W. HESLOP HARRISOS^ ON 



more than one species when Zannichellia and Ranunculus, 

 Zannichellia and Potamogeton, Rvppia and Zostera nana are 

 associated pairs. 



Of these plants, Rttppia alone is intolerant of shallow water 

 • and prefers a depth of about a foot. In the large saltwater 

 lake (for it covers too great an area to be called a pool), 

 Ruppia forms a Submerged Leaf Association belonging to the 

 Saline Aquatic Formation and appears as a dense growth, 

 first developed at a depth of nine inches, and therefore a 

 yard out, extending as far into the water as the eye can see. 

 The following are its members : — 



Ruppia rostellata d Zostera nana 



Ruppia spiralis r 



Between the pans, the wetter and lower sandy soil maintains 

 an open Salicornietum europaeae, amongst which algae like 

 Rhizoclonium flourish. As we approach more thickly colonised 

 drier ground, first Glyceria and Suaeda (the latter toward the 

 hummocks) appear, then Glaux and Spergularia ]o'm company. 

 Next Salicornia wholly disappears and yuncus Gerardi steps 

 in, until finally we have a mixed assemblage of plants reminding 

 one strongly of the freshwater fen association. A typical area 

 chosen for tabulation yielded the following species : — 



Statice limonium vr Cares distans r 



Aster tripolium vr Triticum pungens 



Salicornia radicans vr Glyceria maritima a 



Suaeda maritima .. r G. procumbens 



Plantago maritima a Lepturus tiliformis f 



Spergularia salina ... . f Festuca rubra c 



Glaux maritima Bryum spp a 



Juncus Gerardi /" 



with very many plants found in an average coarse pasture. 

 As the ordinary vegetation of the reclaimed pasture is neared, 

 one by one the halophytes vanish, the last to go being Glaux, 

 Plantago and Spergularia in the order named. 



At times the Salicornietum, in place of passing into the 

 above association, runs up to the barer sandy hummocks 

 bordering the pans ; there a very curious society of the 



