The Willows 



i8i 



shining winter buds are oblong, blunt, 

 about 3 mm. long. The rcniform- 

 orbicular leaves are 3.5 cm. wide or 

 less, rather firm in texture, smooth, 

 rounded, or some of them very blunt- 

 pointed, slightly heart-shaped at the 

 base, their margins entire, or incon- 

 spicuously undulate, the upper sur- 

 face dull green, the under side pale; 

 the lowest pair of veins are nearly as 

 strong as the mid vein; the shghtly 

 flattened, rather stout yellowish leaf- 

 stalks are 1.5 to 2 cm. long, and a 

 little shorter than the blades, or about 

 as long. At the base of the leaf- 

 blade, on the under side, are two 

 brownish, oblong concave glands, 

 about 1.5 mm. long. 



Fig. 139. Cercis-leaved Aspen 



II. THE WILLOWS 



GENUS SALIX [TOURNEFORT] LINN^US 



ILLOWS comprise about 200 species of trees or shrubs principally of 

 the north temperate and arctic zones, very few occurring in the south- 

 em hemisphere. Numerous fossil species have also been described. 

 Aside from their value as shade trees and ornamentals and the pro- 

 tection of the banks of streams, they are not so important economically now, as 

 in former times, when their flexible twigs and bark were more largely used as a 

 coarse fiber and their herbage as fodder. They are still very important in bas- 

 ketry; the bark is used in tanning and very sparingly in medicine; the wood is used 

 to some extent in Europe but ver}^ httle in this countr}', except for fuel and for 

 charcoal, which is preferred for medicinal use and is also used as black crayon 

 by artists. 



They have soft, brittle, usually light-colored wood, single-scaled buds, which 

 are mostly lateral. The leaves are usually narrow and short-stalked, persistent 

 in a few species, their stipules often very large and broad. The flowers are dioe- 

 cious, in cylindric catkins with entire bracts, the staminatc usually dense, erect, 

 spreading or drooping, the flowers with i to 10, usually 2 stamens, their filaments 

 usually distinct. The pistillate catkins are erect or spreading; the ovary sessile 

 or very short-stalked; style short or thread-Hke; stigmas 2, entire or 2-partcd. 

 The fruit is a dr}' capsule, usually 2-valved; seeds very small and numerous, nar- 

 rowed at each end and surrounded by a dense tuft of hairs. 



