2 JUNIPEEACEAE. 



Scales of the ovulate aments stout, each with a short tip which scarcely equals the 



body in length. 1. P. echinata. 



Scales of the ovulate aments slender, each with a subulate tip 



several times the length of the body. 



Cones conic when closed, ovoid when open : twigs glaucous. 2. P. virginiana. 



Cones ovoid when closed, globose-ovoid or depressed when 



open : twigs yellow. 

 Scales of the ovulate aments recurved : cone-scales with 



rather thin appendages, the spines recurved. 3. P. rigida. 



Scales of the ovulate aments ascending : cone-scales with 



thick appendages, the spines incurved. 4. P. pungens. 



1. P. echinata Mill. A tree becoming 40 m. tall, the bark very rough and 

 coarsely furrowed. Leaves in 2 's or 3 's, deep-green, 8-12 cm. long, slender ; 

 sheath 10-15 mm. long: cones 5-6.5 cm. long, ovoid when open, each scale- 

 appendage armed with a slender spine. N. Bare, apparently only near Man- 

 heim. Sandstones and shales. SHORT-LEAF. YELLOW-PINE. 



2. P. virginiana Mill. A tree becoming 36 m. tall, the bark rough, flaky, the 

 twigs glaucous. Leaves in 2 's, deep-green, 4-7 cm. long, rather stout ; sheaths 

 5-8 mm. long: cones 5-7 cm. long, ovoid when open, each scale-appendage with 

 a curved spine. N.S. Eather common, usually in poor soil on ridges. 

 Sandstones and shales, schists. SCRUB-PINE. JERSEY-PINE. 



3. P. rigida Mill. A tree becoming 25 m. tall, the bark very rough, the twigs 

 yellow. Leaves in 3's, bright-green, 6-12 cm. long; sheaths 10-15 mm. long: 

 cones 4-7 cm. long, globose-ovoid or depressed when open. N.S. Rather 

 rare, usually on rocky ridges. Sandstones and shales, schists, and more com- 

 mon on serpentine. PITCH-PINE. 



4. P. pungens Lamb. A tree becoming 18 m. tall, the bark rather smooth but 

 flaky. Leaves in 2 J s, bright-green, 5-10 cm. long, stout ; sheaths less than 1 

 cm. long: cones 8-12 cm. long, very persistent, globose-ovoid or depressed when 

 open. Lower Susquehanna valley. Bare, confined to the dry precipitous river 

 banks and neighboring islands. Schists. TABLE-MOUNTAIN-PINE. 



2. STROBUS Opiz. Leaves needle-like, in 5 's, mostly with 1 fibro-vascular 

 bundle each. Cones drooping: scales leathery, with neither dorsal appendages 

 nor spines. Seeds samara-like. 



1. S. Strobus (L.) Small. A tree becoming 52 m. tall, with relatively smooth 

 bark and approximately whorled branches. Leavest 5-10 cm. long, glaucous, 

 very slender: cones narrow, 1-2 dm. long, often curved. N.S. Not common, 

 growing generally as solitary specimens in woodlands. Sandstones and shales, 

 schists. Spr. WHITE-PINE. 



3. TSUGA Carr. Leaves separate, distichously spreading: blades linear, 

 glaucous beneath. Pollen-sacs opening transversely. Ovulate aments with 

 inconspicuous bracts. Cones drooping. 



1. T. canadensis (L.) Carr. A tree becoming 31 m. tall. Leaves loosely 

 spreading, 6-14 mm. long, obtuse at the apex: staminate flowers about 2 mm. 

 in diameter: cones 18-23 mm. long; scales suborbicular : seed-wings mainly 

 less than 1 cm. long. N.S. Eather common, generally in ravines. Sand- 

 stones and shales, schists. Spr. HEMLOCK. SPRUCE-PINE. 



FAMILY 2. JUNIPERACEAE. JUNIPER FAMILY. 



Mostly evergreen, often resiniferous shrubs or trees, with fibrous 

 shreddy bark. Leaves mainly appressed scales, sometimes subulate and 

 spreading. Ovulate aments with bractless scales. Ovules erect. Cone of 

 dry often peltate scales, or baccate or drupaceous. Seed wingless, or 

 winged, the wing a portion of the testa. 



