lo 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 ciuite 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; irait a 



dry cone 9 



9. Scales of the carpellate cone several-seeded Cupressus 



9. Scales of the carpellate cone 2-seeded Chamaecyparis. 



Class, CONIFERAE. 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, cotyledons 2-15, always free; sperm cells 2, not 

 motile, no cilia being present. 



Order, FINALES. 



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 woodv, with numerous car- 

 pels. Important lumber and turpentine trees. 



1. Dwarf branches with 5 foliage leaves; ovuliferotxs 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 nonnally with 2 foliage leaves 3 



3. Twigs glaucous; leaves slender, 23^-5 in. long; buds not very resinous; 



prickles of the ovuliferous scales short and small. . . .P. echinata. 



3. Twigs glaucous; leaves stout, lJ^-23^ in. long; buds very resinous; 



prickles of the ovuliferous scales long and stout. . . .P. virginiana. 



