81 



BLACK SPRUCE. 

 Picea mariana, (Miller) BSP. 



FORM A small tree usually attaining a height of 20-30 ft. with a diameter of 1 ft., but 

 may reach a height of 100 ft. with a diameter of 3 ft. Trunk straight, continuous, very taper- 

 ing, bearing irregular, rather short, horizontal branches, often with ascending tips which give 

 the tree a very narrow, irregular, conic form. 



BARK Up to * of an inch in thickness and roughened by irregular, thin, close, grayish- 

 brown scales. See Fig. 51. 



TWIGS Rough, stout, brown to yellowish-brown, covered with pale to black hairs. 



BUDS Ovoid, sharp-pointed, i-J of an inch long, covered with overlapping, sharp-pointed, 

 reddish-brown scales. 



LEAVES About 1-2 of an inch long, 4-sided, bluish-green, rounded at apex, straight or 

 slightly curved, without real leaf-bases, but resting on decurrent projections of bark known as 

 sterigmata. 



LEAF-SCARS See "Leaf -Scars" under Red Spruce. 



FLOWERS Appear about May. Staminate and pistillate flowers occur on same plant but 

 often on different parts of it. Staminate sub-globose, almost sessile, i of an inch long, reddish 

 in color. Pistillate oblong, cylindrical, i of an inch long. 



FRUIT A cone about li inches long, short-ovoid, short-stalked, maturing at the end of 

 the first season; core-scales rounded, dull grayish-brown with jagged margin. 



WOOD Non-porous; with resin passages present; light, soft, not strong, pale yellowish- 

 white in color. Weighs 32.86 Ibs. per cubic foot. Used in the manufacture of paper pulp 

 and occasionally in lumber. 



DISTINGUISHING CHARACTERISTICS See "Distinguishing Characteristics" under Red Spruce 

 page 80. 



RANGE It is a transcontinental species extending from Labrador to Alaska and south to 

 Pennsylvania and Wisconsin. 



DISTRIBUTION IN PENNSYLVANIA Frequents swamps, rather common along lakes and in 

 swamps of Monroe and Pike counties and in Bear Meadows, Centre and Huntingdon counties. 

 Also reported in Cambria, Clinton, Lackawanna, Lycoming and Mifllin counties. 



HABITAT The Black Spruce, also known as Swamp Spruce, usually frequents cold, poorly 



drained swamps throughout its range. It sometimes ascends well drained hillsides, but is 



usually stunted in such situations. It makes its best growth on moist alluvial soils and is 

 very tolerant of shade. 



IMPORTANCE OF THE SPECIES The Black Spruce is of little commercial importance in 

 Pennsylvania and should be considered for forestry purposes in extremely swampy locations 

 only, where other more valuable species will not grow. It cannot be recommended for orna- 

 mental planting since other species of Spruce far surpass it for this purpose. 



