h\ \ - PO I Hi- SPE< IES 

 The l*in* - 



A. Leaves 2 to 3 in each cluster, stiff and harsh 

 1.1 2 in each cluster 



- l 1 - to 3 inches long; bark in top of tree reddish-brown, 

 more or ■ aly Scotch Pine, p. 21. 



to 6 inches long; bark in top of tree dark graj 

 black, not scaly Austrian Pine, p. 19. 



2. Leaves 3 in each cluster, 3 to <> inches lon| rk more or l< 

 ilv Western Velio* Pine, p. 23. 



!:. Leaves 5 in each pluster, lax and Boft white Pine, p. 17. 



The Spruces 



A. . to 1 inch long, not sharp-pointed, not bluish 



1. Cones 1 to 2 inches long, maturing the first Beason; leaves 111— 

 smelling when bruised White Spruce, p. 



2. Cones 3 to <> inches long, maturing the second season; leave- not 

 ill-smelling when bruised Norwaj Spruce, p. 27. 



B. Leaves 1 to 2 inches long, very -harp-pointed, bluish, especially on the 

 young growth; cones 2 to :'. inches long Blue Spruce, p. 27. 



The Willows 



A. Leaves broadly or narrowly lanceolate; stamens 3 or more; trees 20 

 to 50 feet tall* 



1. Leaves broadly lanceolate or lanceolate-ovate; petioles Blender 



Almond-leaf Willow, p. 



2. Leaves narrowly lanceolate; petioles short Black Willow, p. 



B. Leaves linear or linear-lanceolate; stamens 2; trees usually less than 

 20 feet tall Sandbar Willow, p. 41. 



The Poplars and C'ottonwoods 



A. Petioles and lower surfaces of leaves densely white-hairy; upper sur- 

 faces dark green and shining White Poplar, p. 51. 



B. Petioles and lower surfaces of leaves not white-hairy 



1. Petioles cylindrical, not flattened; leaves ovate-lanceolate, often 

 quite odoriferous Balsam Poplar, p. 4">. 



2. Petioles strongly flattened 



a 1 Buds resinous or sticky; leaves not orbicular 

 b 1 Leaves green on both si- 



c 1 Leaves broader than long; lateral branches abruptly 

 ascending; crown very narrow and congested, often 

 with many dead twigs Lombardy Poplar, p. pi. 



( Leaves longer than broad; lateral branches wide- 

 spreading; crown open 

 d 1 Leaves broadly deltoid, often heart-shaped at the 



base I ommon Cottonwood, p. 



d" Leaves ovate-lanceolate, wedge-shaped at the 

 base, with long tapering point 



narrow-leaf Cottonwood, p. 



d Leaves rhombic-lanceolate, wedge-shaped at the 

 base, abruptly pointed 



Rydberg*! Cottonwood, p. 53, 

 a* Buds slightly or not at all resinous; leave- nearly orbicular, 



in almost con-taut vibration Quaking \»pen, p. 



The Walnuts 



A. Nut globular <>r -pherieal; leaflet- 1 •". t<> 2".; pith pale brown or yellow; 

 tree Common Black Walnut, p 



B. Nut ovoid or oval, pointed; leaflets 11 to 17; pith dark choco 

 brown; tree not common Butternut, p. 



—1.3— 



