I2O 



A US TRALIAN A CA CIA. 



[CHAP. 



The typical leaves of Acacias are pinnate, with a 

 number of leaflets. On the other hand, many of the 

 Australian Acacias have leaves (or, to speak more 

 correctly, phyllodes) more or less elongated or willow- 

 like. But if we raise them from seed we find, for 

 instance, in Acacia salicina, so called from its re- 

 semblance to a Willow, that the first leaves are 

 pinnate (Fig. 75), and differ in nothing from those 



FIG. 75. Seedling of Acacia salicina. 



characteristic of the genus. In the later ones, how- 

 ever, the leaflets are reduced in number, and the 

 leaf-stalk is slightly compressed laterally. The fifth 

 or sixth leaf, perhaps, will have the leaflets reduced 

 to a single pair, and the leaf-stalk still more flattened, 

 while, when the plant is a little older, nothing remains 

 except the flattened petiole. This in shape, as already 

 observed, much resembles a narrow willow-leaf but 

 flattened laterally, so that it carries its edge upwards 



