1 14 Plants and their Ways in South Africa 



Sow Mimosa seeds, those of the Karroothorn and Black- 

 wood, or the Port Jackson " Willow ". Watch the seeds of 

 both come up " with a loop," bringing their cotyledons with 

 them. On the first leaves note the little bristle-like stipules. 

 Can you see them on both kinds of seedlings ? Are the next 



FIG. 101. The Black-wood trees lose all trace of the compound leaves 

 they had as seedlings. 



leaves the same in each. Watch the seedlings until you find 

 how the Port Jacksons get their long narrow leaves and the 

 Mimosas get their thorns. 



When petioles flatten and take the place of the usually ex- 

 panded portion of the leaves, they are called phyllodes (hav- 

 ing the form of leaves). The Mimosa and the Port Jackson 

 look very unlike as trees. But their early history shows that 



