60 TREES OF THE NORTHERN UNITED STATES 
CC. Leaflets broader and serrate; usually large trees, 23. Zisculus. 
DD. Leaves with radiating ribs. (FF.) t 
DD. Leaves with feather-veining. (EE.) 
EE. Leaves 2-6 in. long; flowers small, in large, dense, ter- 
minal clusters: .4sci64 gecesi he Mend aa eas ea se 62. Syringa. 
EE. Leaves 1-4 in. long; flowers in pairs.. ..... 48. Lonicera. 
FF. Leaves large, 6 in. or more long; two almost hidden buds, 
one above the other, in the axils of the leaves on the rapid- 
growing branches; flowers large, purple, blooming in early 
spring; fruit rounded pods ...... ........... 64. Paulownia. 
FF, Leaves large, 6 in. or more long; flowers large, white, bloom- 
' ing in June; fruit long pods.................... 65. Catalpa. 
FF. Leaves 2-4 in. long, with red stems ...... 3. Cercidiphyllum. 
GG. Leaves scattered singly over the stem, not in bundles or 
clusters. (JJ.) 
GG. Leaves in large or small clusters. (HH.) 
HH. Clusters in whorls of many leaves around the stem like an 
UMbC a. .cvknccccvuncnes sa raceraneewess 100. Sciadopitys. 
HH. Leaves clustered in bundles of 2-6 .. .......... 93. Pinus. 
HH. Leaves clustered in bundles of over 8. (II.) 
II. Leaves deciduous, soft ........ 0... cece eee 97. Larix. 
II. Leaves evergreen, rigid ....... ......-..e eee 98. Cedrus. 
JJ. Leaves hardly evergreen; spray quite slender. (ZZ.) 
JJ. Leaves fully evergreen. (KK.) 
KK. Leaves awl or scale shaped, and mainly appressed to the 
stem. (WW.) 
KK. Leaves linear or needle shaped, and decidedly spreading 
from the stem, though sometimes with a decurrent base. 
(LL. ) 
LL. Leaves narrowed to a distinct though short stem. (RR.) 
LL. Leaves sessile; if narrowed, not so abruptly as to form a 
petiole. (MM.) 
MM. Leaves opposite or whorled on the stem. (PP.) 
MM. Leaves rather spirally arranged around the stem, not just 
opposite. (NN.) 
NN. Leaves linear to lanceolate, fiattened, spreading quite 
squarely from the stem. (00.) 
NN. Leaves not flattened but 4-sided, curved, gradually enlarging 
from the tips to the bases, which are decurrent, and on the 
young twigs completely cover the stem ; cones rounded, their 
scales not lapping............. i Winelew Gre 105. Cryptomeria. 
OO. Leaves about linear in form, of nearly the same width 
throughout, and usually fastened to the cylindrical stem bya 
distinct disk-like base; cones erect; scales lapping. 96, Abies. 
