636 BLACK POPLAR. 



also gummy and of a greenish-yellow colour. The young catkins 

 are at first erect, bullet-shaped, and about an inch in length. The 

 stamens, packed closely together, are hidden under a downy white 

 covering. As the catkins lengthen they curve over, and the bright 

 crimson colour of the anthers is seen, for the down has become 

 relatively unimportant, and the florets are set well apart from one 

 another on the central pedicel of pale yellow which supports them. 



Each floret grows on a short foot-stalk, and springs from the 

 main pedicel. In its next stage the catkin becomes pendent, and 

 grows to a length of three to four inches ; next the pollen-sacs open, 

 and a yellow pollen-dust covers the catkin, over which it is scattered. 

 The brown cases, empty but for some traces of pollen still adhering 

 to them, make the catkin look very soft and give it a yellow tinge. 



From two to five catkins hang on a twig, at some distance apart, 

 the uppermost one being found just below the terminal leaf-bud. 



The Female Catkin. The seed-vessels are arranged spirally at 

 regular intervals along a central support, which, like themselves, is 

 of a bright yellowish-green, and to which each vessel is attached 

 by a tiny green stalk. The seed-vessels are egg-shaped, and end 

 above in two-lobed stigmas ; each one is marked off into four sections 

 by indented lines drawn from tip to base, and is provided with 

 a fleshy covering ; subtending each seed-vessel is a hairy bract. 



When the seeds are ripe, the ovary splits open by means of two 

 valves, and the seeds, each of which has now developed a hairy 

 appendage, burst out and form a white downy mass. 



THE LEAVES. 



The sweet-scented young leaves, clinging closely together, gradually 

 push apart the gummy stipules, and emerge at the tip of the bud. 



