The Willows 



i8i 



shining winter buds are oblong, blunt, 

 about 3 mm. long. The reniform- 

 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 slightly 

 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 Ijark is used in tanning and very sparingly in medicine; the wood is used 

 to some extent in Europe but very little in this country, 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 cyhndric catkins with entire bracts, the staminate 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-parted. 

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

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



