274 



The Plant World. 



increases the gap between the marine and terrestrial formations 

 (Fig. 1). The height of this barren zone varies from six to ten 

 meters. 



Inside the harbors as the development of the saltmarsh 

 proceeds, the Spartina glabra association of the lower beach is 

 followed by the Spartina-Juncus association. Spartina patens 

 and Juncus Gerardi are the character plants. With them in 

 varying abundance occur Salicornia mucronata, Juncus balticus 

 littoralis, Glaux maritima, Sueda maritima, Atriplex patula, 

 Plantago decipiens, Triglochin maritima, Spergularia marina, 

 Potentilla Anserina, and Limonium carolinianum. 



At the upper limit of the middle beach, just east of the Mark- 

 land hotel, the saltmarsh passes into the Agrostis-Juncus asso- 

 ciation of the Freshwater Marsh Formation. Part of this area 

 is occasionally invaded by storm waves, but the seepage of 

 fresh water from the adjoining hills is sufficient to overcome the 

 effect of the sea water. Agrostis alba, Juncus balticus and J. 

 effusus compactus are the commonest species. Festuca ovina, 

 Carex stipata, Rumex Brittanica and Aster novi-belgii are of 

 secondary importance. Here and there shrubs and herbs be- 

 longing to the Alnus-Myrica association occur, showing clearly 

 the coming in of this association, to be described later. 



It should be noted that by way of the saltmarsh there is a 

 continuous and definite succession of plant associations fiom the 

 deeper waters of the bay to the upland. 



The Upper Beach. Between the inner and outer False Bay 

 the conflicting currents have built a beach well above the upper 

 wave limit. The materials are mostly large cobbles and pebbles 

 with sand in the interstices. Plant food is at a minimum and 

 extremes of temperature at a maximum. The AmmophUa- 

 Atriplex Formation occupies practically all of this area in the 

 usual open manner. The formation is difficult to chaiacterize, 

 owing to the large number of both weeds and typical beach plants 

 present. The latter class includes Ammophila arenaria, Atriplex 

 patula littoralis, Mertensia maritima, Spergularia marina, 

 Plantago decipiens, Arenaria peploides, Ambrosia artemisiaefolia, 

 and Ligusticum scoticum. To the foimer belong Spergula 

 arvensis, Ranunculus acris, Leontodon autumnalis, Senecio 

 vulgaris, Chenopodium album, Galeopsis Tetrahit, Aster^tardi- 



