262 THE STORY OF PLANT LIFE 



cylindrical, the scales hairless ; the female are not so 

 long, ascending, curved in fruit, the scales shortly- 

 lobed. There are twelve to twenty stamens. The 

 anthers are purple. The stigmas are roundish. The 

 two stigma lobes are short and broad. The capsule 

 is ovoid, stalked, bent back. 



This Poplar is 50 to 60 ft. in height and flowers in 

 March, before the leaves. It is a deciduous perennial 

 tree. 



The floral mechanism adapts the flowers to pollin- 

 ation by the wind, the plant being dioecious. Pollin- 

 ation must therefore be effected by wind or insects. 



The catkins are provided with silky hairs and the 

 seeds are wind-dispersed. 



The names given to the Black Poplar are Cat-foot 

 Poplar, Cotton-tree (from the silky appendages), 

 Devil's Fingers, Pepillary or Popillary, Black Poplar, 

 Old English Poplar, Willow Poplar. 



The tree is much planted, but is not a timber of 

 any value. 



The Black Poplar was said to have been introduced 

 in 1758. 



PoPULUS MONiLiFERA. — Fig. 73 givcs a good idea of 

 the habit of the tree, with its spreading branches. By the 

 side is the Lombardy Poplar, an erect, fastigiate variety 

 of the true P. nigra. 



y^. The Hornwort Group. 

 This group, the Order Ceratophyllacese, includes 

 one genus only, Ceratophyllum, of which there are 



