PINACEAE 



Black Spruce 

 Picea mariana (Mill.) B.S.P. 



HABIT. A tree sometimes 40-80 feet high and 7^-3 feet in 

 diameter, but commonly much smaller; short slender bole, 

 usually pruning poorly; crown open, conical, more or less 

 irregular. 



LEAVES. Spreading in all directions; V4-% inch long; 4— 

 angled; pale blue-green and glaucous; blunt at apex; more or 

 less incurved; hoary on upper surface from broad bands of 

 stomata; lustrous and slightly stomatiferous below; 2 resin ducts 

 in cross section. 



FLOWERS. About Yz inch long; male red; female purple. 



FRUIT. Yi-lVz inches long; ovoid; on strongly incurved, 

 short stalks; cone scales stiff, brittle, rigid, rounded, smooth 

 or erose at apex, puberulous, and dull gray-brown; persistent 

 many years. Seed: y% inch long, dark brown, with pale brown 

 oblique wing 14-% inch long. 



TWIGS. Rusty-pubescent and rather slender; at first green, 

 becoming dull red-brown. Winter buds: Y^ inch long, ovoid, 

 acute, light red-brown, puberulous. 



BARK. Thin, Y^-Yi inch thick; gray-brown; separated into 

 thin, closely appressed scales or flakes; inner bark often olive- 

 green. 



WOOD. Not important except for pulp; used interchange- 

 ably with white spruce. 



SILVICAL CHARACTERS. Very tolerant, recovering from 

 suppression at an advanced age; growth slow; tree rather short- 

 lived, attaining an age of 200 years; shallow, spreading root 

 system; reproduction good on moist sites; lower branches often 

 take root, forming clusters of small trees. 



HABITAT. Hudsonian and Canadian zones; typical of cold 

 sphagnum bogs and swamps, but also found on dry slopes in 

 Northwest; altitudinal range from 100-3,500 feet; with white 

 spruce and tamarack, reaches northern limit of tree growth; in 

 dense, pure stands, or in mixture with tamarack, balsam fir, 

 white spruce, white birch, aspen, etc. 



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