156 
Leaves simple, ete.—Continned. 
Branches unarmed: 
Leaves evergreen—thichish, leathery ; densely woolly or minutely downy on 
the under surface : 
a. Margin more or less indented or sometimes entire : 
Fruit an acom: 
ikeayvies 1 to,2inches long.) ons sae ose eee ea SES 
Keavesi2 todas inches long... 225-7 cece. eee oe eee 
Eruit-a tailed seed; leaves 4 to 14 incheslone-_-..-2-~ 52-2 - seeeae 
b. Margin entire and rolled back; fruit a tailed seed ................. 
Leaves deciduous, thin, not leathery : 
Margin entire; leaves very narrow, less than one-quarter of an inch 
wide: 
Hrenitvalones(6 tol iiches)s pod a se eyes ere eae eee 61 
Margin variously indented, but sometimes entire, or nearly so; leaves 
more than one-quarter of an inch wide: 
a. With fine (not prickle or bristle pointed) 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: 
SMOO UM ONVNOUNSICCS irae eto alee is seater eteaeelee tee eee 82(86) 
White-downy on the under surface .-.... .-- Pe teint eee &3 
Ovate (exceptionally narrow, lance-shaped); smooth both sides- 84 | 
Leaves narrow, lance shaped; branches round; buds not resin- 
ous: WILLOWS: 
Less than 4 an inch wide, mostly ¢ to + of an inch............ 80 
More than $ an inch wide: 
Pale or whitish on the under surface: 
cr or st 
me wm OC 
i) 
Leaf-stems with glands at the base of the blade .......... 79 
eat-stems withoute clang spa sos seme seeeie see etetae aes 78 
Brownish downy on the under surface...........-. Se Se os ees 81 
Bark not bitter: 
Separating (on trunk) into thin papery layers or sheets; seeds _ 
in a deciduous scaly catkin and with wings: 
LIRCHES: 
Coppery-yelloiw; leaves 1 to 17 inches long--. --2-.--)-- ae. eon eae 74 
Chalky-white; leaves 2 to 34 inches long... -- --.- 5 2-<<--s-sce ec 73 
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 upper surface; fruit cherry-like, dry, 
SWCbe ea this S00) i iainetac cc aniarcinyaremeat memes 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: 
Rough; freshly-wounded bark exuding a milky juice....... 64 


