IO 
The Ohio Naturalist. 
[Vol. X, No. 1 
6. Leaves flat all of about the same length; ours a shrub Taxus. 
6. Leaves more or less 4-sided, spreading in all directions Picea. 
7. Twigs decidedly flattened and fan-like, the leaves small, scale-like, 
and appressed, of two types, the dorsal and ventral broader and 
more abrupt at the apex ; scales of the carpellate cone not peltate. 
Thuja. 
7. Twigs little or not at all flattened, the leaves either scale-like, ap- 
pressed, and nearly or quite similar, or subulate and spreading; 
fruit berry-like when ripe or the scales of the carpellate cone 
peltate 8 
8. Leaves all subulate and spreading; or partly scale-like, 4-ranked and 
appressed ; carpellate cone developing into a bluish-black berry- 
like fruit. (Retinispora forms of Thuja might be sought for 
here also) Juniperus. 
8. Leaves all small, scale-like, appressed, nearly or quite similar; fruit a 
dry cone 9 
9. Scales of the carpellate cone several-seeded Cupressus 
9. Scales of the carpellate cone ‘2-seeded Chamaecyparis. 
Class, COXIFERAE. Conifers. 350 species. 
Sporophytes developing as shrubs or large trees, much 
branched, with or without dwarf branches; stems with a normal 
cambium, no vessels in the secondary wood, resin nearly always 
present; leaves mostly small, entire, linear, lanceolate, subulate, 
or scale-like; flowers monosporangiate, monoecious or dioecious; 
seeds and female gametophyte rather small, ovules without pol- 
len-chamber, cotvledons 2-15, always free; sperm cells 2, not 
motile, no cilia being present. 
Order, PINALES. 
Conifers with both the stamens (microsporophylls) and car- 
pels (megasporophylls) in cones, usually numerous. 
Pinaceae, Pine Family. 
Leaf-buds scaly; carpels of the cone numerous, with two 
inverted ovules on the ovuliferous scale ; stamens with two micro- 
sporangia. 
Pinus L. Pine. 
Resinous evergreen trees with small dwarf branches bearing 
2-5, narrow foliage leaves; dwarf branches and ordinary twigs 
covered with scale leaves. Dwarf branches self-pruned after a 
number of years. Carpellate cones woody, with numerous car- 
pels. Important lumber and turpentine trees. 
1 . Dwarf branches with 5 foliage leaves ; ovuliferous scales little thickened 
at the tip P. strobus- 
1. Dwarf branches with 2-3 foliage leaves; ovuliferous scales much thick- 
ened at the tip 2 
2. Dwarf branches with 3 foliage leaves, rarely 2 or 4, the leaves 3-5 in. 
long; carpellate cones ovoid P. rigida 
2. Dwarf branches normally with 2 foliage leaves 3 
3. Twigs glaucous; leaves slender, 2p£ 5 in. long; buds not very resinous ; 
prickles of the ovuliferous scales short and small. . . P echinata. 
3. Twigs glaucous: leaves stout, lj^-2p£ in. long; buds very resinous; 
prickles of the ovuliferous scales long and stout . . P. virginiana. 
