WILLOW FAMILY 
The flowers are dicecious and appear in early spri'g before 
the leaves. 
Cottonwood, Popu- 
Jus deltotdes. Stam- 
inate Aments, 3/ 
to 4’ long. 
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 
Cottonwood, 
Populus del- 
toides. Pistil- 
late Aments, 
3/ to 4’ long. 
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. 
4i2 
