556 



BOTANY 



PART II 



numerous, parietal seeds. 

 a tuft of hairs. 



Seeds without endosperm ; seed-coat with 



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 to 

 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. 560). Willows occur 

 commonly by the banks of streams where their shortly stalked, narrowly lanceolate 

 leaves give them a characteristic appearance. Some species are among the more 



Km. 501. I'upulus nigra. 1, Male inflorescence. S, Female inflorescence. ./'. .Male (lower. 

 A, Female flower. ~>, Fruit. 6', Seed. (1, 3, f nat. size ;.;->;. enlarged.) 



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

 stems, only the young shoots projecting from the soil (cf. Salix polaris, Fig. 198). 

 Populus has anemophilous flowers ; disc cup-shaped ; no secretion of nectar. The 

 long-stalked circular 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. 561). 



OFFICIAL. SALICIX is obtained from the bark of species of Salix and Populus. 



Order 4. Quereiflorae 



Trees or shrubs usually with entire leaves and deciduous stipules. 

 Monoecious. Male flowers in catkins. Ovary inferior ; ovules pendu- 

 lous. Fruit, a one-seeded nut. Endosperm wanting. Anemophilous. 



