DIV. n 



ANGIOSPERMAE 



615 



This family is mainly represented in the north temperate zone. Salix, Willow, 

 and Populus, Poplar, are the only genera. Salix has erect catkins and is adapted 

 for pollination by insects ; in relation to this, nectar is secreted by small scales 

 at the base of the flower. Male flowers scented ; pollen sticky. The number of 

 stamens varies from 2 to 5 in the different species. Bracts entire (Fig. 611). 

 Willows occur commonly by the banks of streams. Some species are among the 



FIG. 610. Quercti.? poluni.-utata. A, Flowering branch; B, a male flower (magnified); C, stamens 

 (magnified) ; D, a female flower (magnified) ; E, infructescence ; F, cupule ; G-H, seed. (After 

 SCHIMPER.) 



more abundant plants of high northern latitudes ; they have subterranean, creeping 

 stems, only the young shoots projecting from the soil. Populus has anemophilous 

 flowers ; disc cup-shaped ; no secretion of nectar. The long-stalked roundish leaves 

 of the Poplars give them a different habit from the Willows. Flowers similar to 

 those of Salix but with divided bracts. Catkins pendulous (Fig. 612). 

 SALICIN is obtained from the bark of species of Salix and Populus. 



2K2 



