PINACEAE 29 



11. Pin us pungens Michx. A tree reaching a height of 18 m., with a maximum 

 trunk diameter of about 1 m., the bark rather smooth but flaky. Leaves light green, 2 in 

 a sheath, 5-10 cm. long, stout, rigid : sheaths 12-14 mm. long: staminate aments 1-1.5 

 cm. long : cones 8-12 cm. long, ovoid when closed, globose-ovoid or depressed when open, 

 very persistent, the appendages of the scales very thick, each armed with a stout incurved 

 spine : seeds 6-7 mm. long, the wing fully 2 cm. long. 



In stony soil or on cliffs, Allegheny Mountains and the Blue Ridge from Pennsylvania to northern 

 Georgia, and locally in the contiguous territory. TABLE MOUNTAIN PINE. 



2. CARYOPITYS Small. 



Monoecious evergreen shrubs or trees. Leaves needle-like, 2-3 together, or solitary, 

 each with 1 fibro-vascular bundle, each cluster surrounded at the base by a deciduous sheath. 

 Staminate aments clustered at the ends of branchlets of the preceding year. Anthers 2- 

 celled, each sac opening lengthwise. Pollen-grains with two lateral empty cells. Pistil- 

 late aments borne behind the terminal bud. Cones maturing the second year : scales be- 

 coming leathery, with the dorsal thickenings often minutely spine-tipped. Seed-wing very 

 narrow or a mere margin which remains attached to the scale when the seed falls. 



1. Caryopitys edulis (Engelm.) Small. A tree often becoming 12 m. tall, with 

 irregularly ridged bark. Leaves 2 or rarely 3 in a sheath, 2-5 cm. long, rigid, dark green : 

 sheaths 6-12 mm. long, early deciduous : staminate aments 6-9 mm. long : pistillate aments 

 oblong-cylindric, short-peduncled : cones ovoid, 4-6 cm. long ; scales much thickened back 

 of the apex, each enlargement with a minute incurved tip : seeds ovoid, fully 1 cm. long, 

 the wing about 3 mm. wide, detached from the seeds at maturity. [Pinus edulis Engelm.] 



On limestone bluffs or in arid soil. Wyoming to Texas and Mexico. Spring. NUT PINE. PINON. 



3. STROBUS Opiz. 



Monoecious evergreen trees. Leaves needle-like, mostly with 1 fibro-vascular bundle, 

 5 together, surrounded at the base by a deciduous sheath, the clusters spreading in all direc- 

 tions. Staminate aments in spikes or clusters at the ends of brachlets of the preceding 

 year. Anthers 2-celled, opening longitudinally. Pollen-grains of 3 cells ; 2 lateral cells 

 empty. Pistillate aments slightly elongated, on twigs behind the terminal bud : scales 

 crowded in several series. Cones maturing the second year, drooping : scales becoming 

 leathery, without either dorsal thickening or spine. Seeds winged. 



1. Strobus Strobus (L.) Small. A forest tree of the first economic importance, 

 reaching a height of 52 m., with approximately whorled branches, bark relatively smooth, 

 often shining. Leaves very slender, 5 in a sheath, often rather crowded, 5-10 cm. long, 

 glaucous, nearly triangular in cross-section : sheaths deciduous or fugaceous : staminate 

 aments ovoid or oblong, 8-10 mm. long, glaucous, in dense clusters : pistillate aments nar- 

 rowly oblong, about 1 cm. in length, glaucous : cones narrowly cylindric, 1-2 dm. long, 

 somewhat tapering towards the apex, more or less curved ; scales at length loosely spreading, 

 thinnish : seeds elliptic, 6-7 mm. long ; wing usually about 2.5 cm. long. [Pinus Strobus L. ] 



In woods. Newfoundland to Manitoba, south to New Jersey and Iowa, and in the mountains to 

 northern Georgia and Alabama. Spring. WHITE PINE. 



4. PICE A Link. 



Evergreen monoecious trees, with soft wood. Leaves ascending or nearly erect : blades 

 needle-shaped, but short, nearly terete or 4-angled, curved, leaving a prominent base on 

 falling away. Staminate aments arising from the axils of the leaves of the preceding year, 

 or sometimes terminal. Pollen-sacs loosely disposed, opening longitudinally. Pistillate 

 aments terminal : scales closely imbricated : bracts membranous, inconspicuous. Cones 

 maturing the first year, drooping ; scales thinnish, persistent, at length spreading. Seeds 

 samara-like, each with a hyaline wing. The plants flower in spring. 



Twigs stout, copiously pubescent : leaves over 1 mm. broad, blunt or mucronate : cones persistent. 



1. P. Mariana. 

 Twigs slender, glabrate or merely pubescent between the decurrent sterigmata : leaves 



barely 1 mm. broad, acute : cones early deciduous. 2. P. australis. 



1. Picea Mariana (Mill. ) B.S.P. A forest tree reaching a height of 30 m., with a 

 maximum trunk diameter of about 1 m. Bark slightly roughened : twigs stout, stiff, copi- 

 ously pubescent as are usually the sterigmata : leaves stout, curved, 8-12 mm. long, over 1 

 mm. thick, blunt or mucronate, deep green : cones oval or ovoid, 2.5-4 cm. long, persistent. 



In moist soil. Newfoundland to the Northwest Territory, New Jersey and Minnesota, and in the 

 mountains to North Carolina. BLACK SPRUCE. HE BALSAM. TAMARACK. YEW PINE. LASHHORN. 



