SPRUCE AND BALSAM FIR TREES. 5 
The cones (PL 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 (PL 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 
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. 
