i88 



FORMATIONS AND GUILDS 



[Part II 



closed formations of the innermost, where the psammophytic character 

 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 few 

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

 example Juncus maritimus, Cynodon Dactylon, Scirpus Holoschoenus, 

 species of Agropyron, Ephedra distachya, Eryngium maritimum ; also 

 species of plants with extremely deep rhizomes and roots, for example 

 Ammophila arundinacea, Echinophora spinosa, Clematis Flammula. Most 

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



Fig. 102. From the Camargue. Forest of Pinus Pinea with Juniperus phoenicea and other 

 plants as underwood. The depression in the centre is chiefly clad by psammophilous grasses. After 

 Flahault and Combres. 



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

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

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

 the sea and on various kinds of soil. Yet the absence of several species 

 common elsewhere shows that the soil is relatively new. Fig. 102 

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

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

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

 as Rosmarinus officinalis, Phillyrea angustifolia, Cistus salvifolius. The 

 lower sites bear chiefly psammophilous grasses. 



