48 CHINESE ECONOMIC TEEES 



CLASS II. ANGIOSPERMAE 



SALICACEAE 



Leaves alternate with stipules. Flowers dioecious, in catkins. 

 Perianth absent. Stamens 2 to indefinite. Ovary 1 celled; styles 2. 

 Capsule 2-4 valved. Seeds bearded, exalbuminous. 



Two genera and about 200 species, of which Salix is the largest genus, 

 with about 150 species. The family occurs in the N. temperate region, 

 extending into the arctic circle. Salix is a most baffling genus to the 

 systematic botanist because the trees are dioecious, and the species 

 hybridize freely. 



KEY TO GENERA 



I.- Bracts of the flowers incised or fringed ; stamens numerous; 

 stigma elongated Populus, 



II. Bracts of flowers entire; stamens 2-10; stigmas short . . . .Salix. 



SALIX 



Trees or shrubs. Buds covered by a single bud scale, composed of 

 2 connate and coalescent stipules. Leaves deciduous, alternate, simple, 

 stalked, mostly elongated and pointed, pinnately veined; stipules serrate, 

 small and caducous, or large and persistent. Flowers dioecious, in 

 catkins, without perianth, each subtended by a bract with usually entire 

 margins, glandular. Staminate flowers with 2-12 stamens on slender 

 filaments. Pistillate flowers with a single pistil; carpels 2; stigmas 2, 

 entire or bifid. Fruit a capsule dehiscent on top into 2 valves. Seeds 

 minute, dark brown or black, furnished with long, silky hairs. 



About 150 species, mostly shrubs, widely distributed in the Northern 

 Hemisphere, ranging in habitat from low wet ground to Alpine heights. 

 The wood of the genus, for the most part light and soft, is chiefly 

 useful for the manufacture of small ware and for burning for charcoal. 

 Of the arborescent species, the widely distributed Salix alba and Salix 

 fragilis are valuable timber trees, and the wood supplies the best charcoal 

 for the manufacture of gunpowder. The branchlets of the willow are 

 woven into baskets and furniture, and large plantations of the willow 

 trees are expressly maintained as an adjunct to these industries. 



