15G 



Leaves simplo, etc.— Coutinned. 



Branches unarmed : 



Leaves evergreen — iliieldsli, leatlienj ; deusely woolly or minutely downy on 

 tlie under surface : 

 a. Margin more or less indented or sometimes entire : 

 Fruit an acorn : 



Leaves 1 to 2 inches long 69 



Leaves 2 to 3^ inches long 72 



Fruit a tailed seed ; leaves ^ to 1^ inches long 51 



&. Margin entire and rolled back ; fruit a tailed seed 50 



Leaves deciduous, thin, not leathery : 

 Margin entire; leaves very narrow, less than one-quarter of an inch 

 wide: 



Fruit a long (6 to 12 inches) pod Gl 



Margin variously indented, but sometimes entire, or nearly so ; leaves 

 more than one-quarter of an inch wide : 

 a. TTWi fine (not pricMe or bristle j)ointed) teeth: 



Bark bitter ; fruit (seed) borne in deciduous catkins, and when 

 mature, cottony: 

 Leaves broad, triangle-shaped, or ovate (in 84) ; branches often 

 angled; buds resinous: Poplars: 

 Triangle-shaped: 



Smooth on both sides 82(86) 



White-downy on the under surface t?:^ 



Ovate (exceptionally narrow,lance-shaped); smooth both sides. 84 

 Leaves narrow, lance shaped; branches round; buds not resin- 

 ous : Willows : 



Less than ^ an inch wide, mostly ^ to ^ of an inch 80 



More than ^ an inch wide: 



Pale or whitish on the under surface : 



Leaf-stems with glands at the base of the blade 70 



Leaf-stems without glands 78 



Brownish downy on the under surface 81 



Bark not bitter : 



Separating (on trunk) into thin papery layers or sheets; seeds 

 in a deciduous scaly catkin and with wings : 

 Birches : 



Coppenj-yelJow ; leaves 1 to 1^- inches long 74 



ChaVcy-wldte'; leaves 2 to 3^ inches long.. 7:? 



Not separating into layers or sheets ; fruit fleshy, or a winged 



seed in a persistent catkin : 

 Leaves unequal-sided (unsymmetrical), mostly entire, but occa- 

 sionally with small teeth : 

 Very rough on the ux)per surface; fruit cherry-like, dry, 



sweet 63 



Smooth above, hairy on under side ; fruit a flat winged seed — 



samara ; belongs under *' coarse teeth " 62 



Leaves equal-sided (symmetrical) and always toothed on the mar- 

 gin: 

 Rougli ; freshl 5'- wounded bark exuding a milky juice 64 



