36 



toothed or nearly entire; catkins a])i)earing before (precocious), with 

 (ccetancous), or after the leaves (serotinous) ; each jjistillate flower with 

 a little gland at the tiase of the pedicel on the inside. 



A large genus of several hundred species varying from tiny shrubby 

 or suljherbaecous jilants scarcely an inch in height to 0.5 m. (2 feet) 

 or more in diameter, in alluvial lowlands; occurring under Indiana 

 contlitions fioni cold bogs and river banks to dry sand dunes. Willows 

 are used for many purposes, among them ornament, shade, hedges, 

 posts, poles, mattresses, revetments to protect levees, baskets, fish- 

 weirs, whistles, etc., while the wood is used foi' ehai'coal, which is es- 

 pecially prized for gunpowder making, and the bark is used for tanning 

 and furnishes salicin, which is used in medicine as a substitute for 

 quinine and as a tonic and febrifuge. 



Small to largo trees; leaves narro^vl^' to liroadly lanceolate, 



mostly long pointed, finely and rather closelj' toothed; 



flowers appearing with the leaves; capsules not hairy. 



Native trees; leaves green on both sides (No. 1) or white 



(glaucous) beneath (No. 2), and then with very long 



points and long slender twisted ])etioles \ihich are 



never glandular; stamens .'i-.")-? or n^ore. 



Twigs dark green, spreading; leaves narrowly lanceolate, 



gi-een on both sides; petioles short 1 S. nigra. 



T-s\"igs yellowish, somewhat drooping; leaves broadly 



lanceolate, glaucous beneath; petioles long, twisted.. 2 S. amygdoloides. 

 European trees, cultivated for ornament and use; leaves 

 ah\-ays glaucous beneath; stamens always 2. 

 Teeth on edge of leaf S-10 to each cm. (20-2.5 to the inch) ; 



petioles usually glandular; capsules almost sessile. ... 3 fS. alba. 

 Teeth on edge of leaf 6-8 per cm. (1.5-20 to the inch) ; jjeti- 



oles usually glandular; pedicels 0.5-1 mm. long 4 S. fragilis. 



Slirubs or rarely smaU trees; leaves elliptical or oblanceolate, 

 short pointed; margin entire or coarsely wavy or shallow- 

 toothed; flowers before the lea\-es; stamens 2; capsules 

 long, hairy. 



Twigs and leaves not hairy; leaves thin 4 S. discolor. 



Tmgs and sometimes the h«\er suface of the lea\'es densely 



hairy, leaves thicker 5 g, discolor 



erioeephala. 



1. Salix nigra Marshall. Willow. Black Willow. Plate 10. 

 Shrub or tree 5-20 m. (17-65 feet) high, dark green in mass color; 

 bai'k of trunk thick, rough, flaky, dark brown to nearly black; twigs 

 brittle at base, the younger pubescent and green, becoming glabrous 

 and darker ^vith age; buds ovate, small, 2-3 mm. {Vg inch) long; 

 petioles 3-6 or 8 mm. (^-^8 intdi) long; stipules small, ovate to 

 roundish; leaf blades narrowly lanceolate, acute or rounded at base, 

 long-acuminate at the apex, 6-11 cm. (2 liA H inches) long, 7-12 



