SECTION XIV 



CLASS XL SCLEROPHYLLOUS FORMATIONS. 

 BUSH AND FOREST 



CHAPTER LXXXII. SCLEROPHYLLOUS VEGETATION 

 AND FORMATIONS 



THE term ' sclerophyllous ' is employed by Schimper l in connexion 

 with xerophytic bushland and bush-forest in subtropical regions where the 

 rain falls in winter. It refers to the small, thick, coriaceous, entire leaves 

 which are so extremely common in these regions. Such regions with 

 winter-rain are the Mediterranean countries, California, the south-western 

 part of Cape Colony, the coastal parts of West and South Australia, and 

 Chile between 30 and 38 S. In these places the winter is mild, even if 

 slight frosts occur. The rain falls in few but violent showers, but the 

 winter enjoys much sunshine. The summer is dry, and only infrequently 

 experiences a light shower of rain. In the interior of the larger masses 

 of land the rain in winter is often very scanty, for instance, in the Sacra- 

 mento Valley in California, also in the interior of Chile, Spain, and Asia 

 Minor. In such places steppe prevails. But where the winter-rain is 

 more abundant the country becomes clothed with low bushland ; well- 

 grown forest, on the contrary, is rare. 



The prolonged summer-drought is hostile to vegetation. Hence the 

 rarity of larger trees. The trees are small, with gnarled trunks and boughs ; 

 and most of them may occur in the guise of dwarf-trees and shrubs. The 

 leaves of the trees and shrubs are, as a rule, evergreen and protected from 

 desiccation in various ways, yet their structure is not so extreme as that 

 of desert-plants. The most obvious feature is the reduction in size of leaf, 

 for the leaves are small ; leaves of medium size occur only rarely, and then 

 only on shrubs in specially favoured localities. Among the various types 

 of leaf may be mentioned : the ericoid leaf, possessed by Erica, Elytro- 

 pappus Rhinocerotis, and Cliffortia falcata and others ; the pinoid leaf, 

 occurring in many families in Cape Colony ; the linear rolled leaf of 

 various Labiatae ; ternate and pinnate leaves, exhibited by Leguminosae, 

 Pistacia, and Cunonia capensis. Most of the leaves are stiff, thick, strongly 

 cutinized, and rich in sclerenchyma, and also have their intercellular 

 spaces reduced. According to Guttenberg, 2 there is in nearly all Mediter- 

 ranean evergreen sclerophyllous leaves a characteristic mechanism, in the 

 form of supporting cells and cell-walls that act as struts to prevent 

 collapse of the assimilatory tissue. The lower face of the leaf is often 

 very hairy, rarely are both faces tomentose. Bud-scales are uncommon. 



Winter and spring form the true vegetative season of sclerophyllous 

 1 Schimper, 1898. * Guttenberg, 1907. 



