174 CHAPTER XXIII. 



The commonest Cislus and the Helianthemum 

 (Rock Rose) which one meets oftenest are hairy. 

 In the Daphne family, the specific name of the rare 

 Thymelea hirsuta speaks for itself. Lavatera maritima, 

 pearl of the rock-bound coast, is clad in a pale 

 pearly green. Cynoglossum Creticum has " feuilles 

 grisatres pubescentes " ; and the wild Heliotrope is 

 likewise a " friar of orders grey." These examples 

 must suffice. Most of the families represented on 

 the Riviera can show plants similarly shielded from 

 the sun. 



In some cases the leaves are silky underneath. 

 For instance, Genista cinerea. Can this be a protection 

 against the heat radiated from the ground ? It is 

 significant that this shrub lives " sur les collines tres- 

 seches," and is of very small stature, so that the leaves 

 are raised but little from the burning soil. 



Amelamhier, whose cheerful white blossoms light 

 up every rocky gorge, has its buds thickly swathed ; 

 but as the leaves expand they discard the cottony 

 covering. Perhaps, living in more humid spots, it is 

 less liable to be dried up and parched. The tomentose 

 wrapping may serve to guard the buds and the deli- 

 cate young leaves against the attacks of caterpillars. 

 I believe that leaf-hairs frequently serve this purpose. 

 It is certain that we often see trees with glabrous 

 leaves, ex. (jr. willows, completely denuded by 

 different larvae. 



Cistus tuberaria, a conspicuous plant, which we 

 have found whenever we have visited the Esterel, 

 presents a remarkable phenomenon. The leaves of 

 the radical rosette are covered with grey hairs, while 

 these on the flower-scape are green and glabrous. 



