3^4 
The Ohio Naturalist. 
[Vol. V, No. 8, 
KEY TO THE GENERA OF OHIO WOODY PLANTS BASED ON 
LEAF AND TWIG CHARACTERS. 
John H. Schaffner. 
]. Foliage leaves with expanded blades, netted-veincd. 8. 
1. Foliage leaves needle-shaped, narrowly linear, subulate, or scale- 
like; conifers, or in one case a dicot yl with delicate twigs and 
minute leaves. 2, 
1. Foliage leaves fan-shaped with dichotomous venation, a number on 
thick, wart-like, jjersistent dwarf branches. Ginkgo. 
2. With typical dwarf branches, persistent for more than 1 year. .3. 
2. With feather-like dwarf branches, deciduous each year, the linear 
leaves spreading into 2 ranks. Taxodium. 
2. With delicate spray-like twigs deciduous each year; leaves scale- 
like, minute; a dicotyl. Tamarix. 
2. Without dwarf branches. 4. 
,3. Dwarf branches small, self-pruned, with 2-5 foliage leaves. Pinus. 
3. Dwarf branches thick, wart-like, persistent, with numerous decid- 
uous leaves. Larix. 
4. Leaf buds scaly; leaves scattered. 5. 
4. Leaf buds not scaly, naked ; leaves opposite or whorled. 7. 
5. Leaf scar on a sterigma, the twigs covered with scales representing 
the leaf bases, (i. 
5. Leaf scar on the bark; twigs without scales; leaves flat. Abies. 
(3. Leaves flat, those on the up]>er side of the twig much shorter than 
the lateral ones; trees. Tsuga. 
(). Leaves flat all of about the same length ; ours a shrub. Taxus. 
(i. Leaves more or less 4-sided, spreading in all directions. Picea. 
7. Foliage leaves small, scale-like, appressed, opposite, 4-ranked, 
closely covering the twigs which are decidedly flattened and fan- 
like; leaves of two shapes, the dorsal and ventral broader and 
less acute than the lateral ones; scales of the carpellate cone not 
peltate. Thuja. 
7. Foliage leaves small, scale-like, appressed, opposite, 4-ranked, 
closely covering the slightly flattened twigs which are not very 
fan-like; leaves nearly or quite similar; scales of the carpellate 
cone peltate. Chamaecyparis. 
7. Foliage leaves of two tyjies, scale-like and subulate, opposite or in 
threes; the scale-like leaves 4-ranked, appressed, causing the 
twigs to appear quadrangular, the subulate leaves spreading; 
one or both types of leaves on a plant; carpellate cone developing 
into a bluish-black berry-like fruit. Juniperus. 
— 8 — 
8. Leaves alternate. 9. 
8. Leaves opposite or whorled. 110. 
0. Leaves simple. 10. 
0. Leaves compound. 93. 
10. Leaves pinnately veined or with a simple midrib. 11. 
10. Leaves palmately veined or at least with 2 or more prominent side 
ribs coming from near the base of the blade. 74. 
11. Leaves not revolute-margined when fully expanded. 12. 
11. Leaves decidedly revolute-margined, evergreen, thus ajtpcaring on 
wood of the previous season. 90. 
12. Leaves truncate or broadly emarginate; with complete stipular 
rings at the nodes. Liriodendron, 
Leaves entire. 13. 
12 . 
