•iI2 



ZONES AND REGIONS [Pt. Ill, Sect. II 



dimensions (Lencadendron argenteum, Protea macrophylla, P. coccinea). Their 

 epidermis always possesses very thick outer walls. 



On comparing sclerophyllous plants with other xerophilous woody plants, 

 what strikes one most, besides the evergreen nature of the foliage, is the 

 absence of one of the commonest protective means against threatened 

 desiccation, namely water-reservoirs ; these are not found in the leaves, nor 

 yet in the roots. We have already noted that a protective tomentum on 

 the upper surface of the leaf is usually absent, and that pinnate leaves, so 

 common m other xerophilous communities, are rare. Thorns, which are 

 also common in other xerophilous plants, are almost unknown among sclero- 

 phyllous plants, and vegetative buds in 

 most cases are devoid of any protective 

 envelope of scales. 



If sclerophyllous plants completely 

 dominate vegetation in the districts they 

 characterize, they are nevertheless al- 

 ways accompanied byplants of a different 

 structure and mode of life. Among 

 these, bulbous and tuberous plants take 

 a prominent place. These are always 

 to be found in close proximity to the 

 sclerophyllous bush-wood, and usually in 

 very great diversity of form. The wealth 

 of Mediterranean countries, Cape Co- 

 lony, Chili, and California in such plants 

 is generally known, and the same fact 

 is stated of South and South-West Aus- 

 tralia. Nowhere else in other districts 

 Fig. 273. Sclerophyllous flora of Cape do they form so essential a component 



Colony. Grubbia stricta, A. DC. (Grubbia- 



of the vegetation. Mingled with the 



ceae). Natural size. After Hieronymus, in 



Engler und Prantl, Die natiirlichen Pflanzen- sclerophyllous plants one may see 1SO- 



familien. , , ,, , 1 



lated aphyllous woody plants, some 

 succulent plants, such as Cactaceae in America, Mesembryanthemum at the 

 Cape ; but these plants are by no means rich in forms, and are always 

 emigrants from other districts, particularly from deserts. Woody lianes 

 are rare, and very thin-stemmed ; on the other hand, herbaceous climbers 

 are often common. Except in the case of the above-mentioned succulent 

 plants, there is nothing characteristic about the herbs. Mosses and lichens 

 are either very rare upon, or completely absent from, the bark of trees. 

 The more highly organized epiphytes never occur, even although they 

 appear in neighbouring districts with similar or lower temperatures, as in 

 Cape Colony and Chili. 



