i88 



FORMATIONS AND GUILDS 



[Part i: 



closed formations of the innermost,, where the psammophytic cliaracte: 

 is only weakly exhibited. 



The vegetation of the outermost dunes is scanty, but highly character- 

 istic. There are found various grasses, sedges and rushes, besides a fev 

 other plants with long creeping rhizomes, taking root at the nodes, fo: 

 example Juncus maritimus, Cynodon Dactylon, Scirpus Holoschoenus 

 species of Agropyron, Ephedra distachya, Eryngium maritimum ; als( 

 species of plants with extremely deep rhizomes and roots, for exampl' 

 Ammophila arundinacca, Echinophora spinosa. Clematis Flammula. Mos 

 of the species have a halophilous as well as a psammophilous character 



Fig. 102. From the Camargue. Forest of I'lnus Pinea with Junipenis phoenicea and oth 

 plants as underwood. The depression in the centre is chiefly clad by psammopliilous grasses. Aft 

 Flahault and Combres. 



On the oldest dunes, but also on flatter elevations (' radeaux ') coev. 

 in origin, the edaphic influences are much reduced. Trees and tall shrul 

 appear, and most of the species there are the same as occur far fro 

 the sea and on various kinds of soil. Yet the absence of several speci'i 

 common elsewhere shows that the soil is relatively new. Fig. ic; 

 presents a picture from the older dunes. The higher places are occupit 

 by a pinewood the rich underwood of which is chiefly formed by Juniper 

 phoenicea, but by other characteristic Mediterranean shrubs as well, sue 

 as Rosmarinus officinalis, Phillyrea angustifolia, Cistus salvifolius. Tl 

 lovv-er sites bear chiefly psammophilous grasses. 



