SPRUCE AND BALSAM FIR TKEES. 5 



The cones (PI. I, a) are ripe by the end of August, when they are 

 pale ashy brown, and within a few weeks afterwards they shed their 

 .small winged seeds (PI. I, b). Because of their very stout, firm 

 stems the cones of this spruce remain firmly attached to the branches 

 for very many years, a characteristic which roughly distinguishes 

 this tree from other species of its range. The stems of the cones are 

 curved downward or inward toward the branch. Scales of the open 

 cones are peculiarly stiff and resistant to pressure of the hand, but 

 are easily broken if squeezed together. The seeds (PI. I, b) are a 

 deep chocolate brown. Seed-leaves, usually 6, are about one-half inch 

 long or shorter. 



Black spruce wood is usually of a clear, very light yellow color. It 

 is characterized by a thin layer of sapwood and very narrow annual 

 rings of growth. It is heavier than that of any other native spruce, 

 a cubic foot of seasoned wood weighing nearly 33 pounds. The color 

 of wood from different individual trees of this species often varies 

 greatly, so that it is easy to confuse the wood with the pale or yellow- 

 ish-white wood of the white spruce, with which black spruce wood 

 may be mingled occasionally as lumber. Black spruce is commer- 

 cially the least important of all the eastern spruces, chiefly on account 

 of the small size of the tree, which in the eastern part of its range 

 is cut mainly for paper pulp. 1 



OCCURRENCE 2 AND HABITS. 



Black spruce is essentially a swamp tree, characteristic of cold, wet 

 bogs and margins of lakes (Map No. 1). It grows on clay and heavy 

 glacial drift, and occasionally also on high, well-drained hill soils, 

 where it is much less abundant than in moister sites and is small and 

 stunted. The best growth is found in constantly moist, well-drained 

 alluvial soils, while the tree is most abundant in wet soils. Depth of 

 soil is not essential, owing to shallow root system. The vertical range 

 is imperfectly known at present, but the tree occurs more or less at 

 elevations between about 100 and 3,500 feet. Black spruce forms 

 pure forests over limited or small areas, the largest and best stands 

 occurring in moist, well-drained alluvial bottoms. It also grows in 

 mixed stands associated with tamarack, black cottonwood, balm of 

 Gilead, aspen, willows, and alders. 



1 Considerable quantities of " spruce gum " are collected from injured places in the 

 trunks of black spruce, chiefly, however, in the tree's eastern range, where the white and 

 red spruce also yield a part of this crude product, which is later refined and prepared for 

 market. 



2 William Aiton states in his " Hortus Kewensis " that black spruce was introduced into 

 England in 1700. According to Elwes and Henry (The Trees of Great Britain and Ire- 

 land, VI, 1377, 1912), black spruce planted near Colesborne attained a height of 56 feet 

 and a diameter of about 11 inches in 55 years. Trees planted in Scotland in 1832 were 

 40 feet high in 1904. The trees planted in moist or wet situations appear to be thrifty, 

 while those set in drier places have proved to be short-lived. 



