WILLOW FAMILY 



The flowers are dioecious and appear in early spring before 

 the leaves. They are borne in long, drooping, sessile or 

 pedunculate aments which are produced from 

 buds formed in the axils of the leaves of the 

 previous year. The pistillate aments lengthen 

 very considerably before maturity. The flow- 

 ers are solitary, each one seated in a cup- 

 shaped disk which is borne on the base of a 

 scale which is itself attached to the rachis of 

 the ament. The scales are obovate, lobed and 

 fringed, membranous, hairy or smooth, usually 

 caducous. The staminate flowers are without 

 calyx or corolla and consist simply of a group 

 of stamens, four to twelve, or 

 twelve to sixty, inserted on a 

 disk ; filaments short, pale yellow; 

 anthers oblong, purple or red, in- 

 trorse, two-celled ; cells opening 

 longitudinally. 



The pistillate flower is equally destitute of 

 calyx and corolla and consists of a one-celled 

 ovary seated in a cup-shaped disk. The style is 

 short, stigmas two to four, variously lobed ; 

 ovules numerous. The fruit is a two to four- 

 valved capsule, ripening before the full develop- 

 ment of the leaf ; greenish or reddish-brown. 

 The seed is light brown and surrounded by a 

 tuft of long, soft, white hairs. 



Populus is the oldest type of dicotyledonous 

 plants yet identified. When Sequoias, Pines and 

 Cycads made up the bulk of the cretaceous forests of Green- 

 land, the Poplar alone of deciduous trees waved its fluttering 

 leaves among their dark branches. 



Cottonwood, Popu- 

 lus deltoides. Stam 

 inate Aments, 3 

 to 4' long. 



Cottonwood, 

 Populus del- 

 toides. Pistil- 

 late Aments, 

 3' to 4' long. 



412 



