FOREST TREES OF THE PACIFIC SLOPE. 87 



tinguishing this tree from its somewhat similar related species. The stems of 

 the cones are very stout, firm, and curved downward or inward toward the 

 branch. The open cone-scales are peculiarly still* and resistant to pressure of 

 the hand; but are easily broken if squeezed together. The seed is a deep 

 chocolate brown. Seed-leaves, usually (i. about one-half inch long or shorter. 

 Wood usually a clear, very light yellow. The common color of this wood, also 

 of that of the white spruce and to some extent of the red spruce, with which it 

 may be mingled sometimes as lumber, is not an entirely sale character to rely 

 upon for identification. The color of wood from differenl individuals of the 

 same species often differs greatly, so that it is easy to confuse it with the 

 pale or yellowish white wood of the two other spruces. Black spruce wood is 

 mainly very fine-grained. Of the other eastern spruces it is the least important 

 commercially, mainly on account of its small size. 



Longevity. — Doubtless a moderately long-lived tree; average observed sizes 

 are from 125 to 200 years old. Stunted trees growing in very wet situations 

 and scarcely 2 inches in diameter are often from 50 to nearly 80 years old, 

 but appear to be thrifty, considering the unfavorable situation. Further records 

 of longevity are desirable. 



RANGE. 



Newfoundland to Hudson Bay and northwestward to Alaksa ; southward in Michigan, 

 Wisconsin, Minnesota, and in the eastern mountains to North Carolina and Tennessee. 

 Northwestern range very imperfectly known. It is probably much the same as thai 

 of white spruce, but further accurate field observations are required to establish the 

 coincidence of ranges. It seems likely that black spruce will prove to be far less 

 abundant in Alaska than the while spruce. 



Canada. — Abundant in Great Plains, especially north of Saskatchewan and on Beaver 

 and Athabaska rivers, extending westward to eastern slopes of Rockies and southward 

 to tributaries of Elbow Elver, :'»0 miles from Calgary. Northward, in Great Plains, 

 through Peace and Mackenzie river valleys, to within 20 miles of Arctic Ocean and 

 from mouth of Coppermine River (long. llfi°) westward to Alaska. Crosses Conti- 

 nental Divide into interior plateau of Rockies farther south than white spruce, being 

 common on high plateaus of Upper Fraser and Blackwater rivers Hat. 58°) and north- 

 ward on Btiklne, Dease, Liard, Prances, and Telly rivers. Abundant from Pelly River 

 to McQuestion River (tributary Stewart River) at about 3,500 feet elevation: at Daw- 

 son and westward on Yukon River and southward on White River to a point 212 miles 

 from its mouth. 



Alaska. — There are no definite records for Yukon Valley, over which this tree very 

 probably extends, northward to south slopes of Endicott Range, westward to Bering 

 Sea, and southward to inland slopes of Pacific coast ranges. Records are avail- 

 able for its occurrence on Cook Inlet, an arm of the Gulf of Alaska. Here it occurs 

 sparingly at about 2,000 feet elevation in swamps of the plateau on Kenai Peninsula, 

 especially on Chicaloon Flats, and in peat bogs at Hope, Sunrise, and Tyonek, on Cook 

 Inlet coast. 



OCCURRENCE. 



Essentially a swamp tree, characteristic of cold, wet bogs and margins of lakes; grows 

 occasionally on high, well-drained hillsides, but is less abundant here than in wel sites. 

 and is small or stunted. Best growth in constantly moist, alluvial, well-drained soils, but 

 most abundant in wet soils. Depth of soil is not essential, owing to shallow root system. 

 Grows on clay and heavy glacial, drift, and sometimes even in sandy, hill soils, but of 

 poor growth in such soils. 



In east, forms pure forests over limited and extensive areas, occurring also in mixed 

 stands. In northwest, best growth in limited or small areas of pure stand in moist, 

 well-drained alluvial bottoms of Athabaska River, and in river valleys in Saskatchewan 

 and north Manitoba. Valley of Yukon River, grows in wet localities, usually over buried 

 glaciers. Not common immediately on banks of the Yukon, but abundant in Pelly River 

 drainage on swampy parts of bottoms, on moss-covered north slopes, and at heads of 

 streams on low, broad divides. In mixture, associated with tamarack, black cottonwood, 

 balm-of-gilead, aspen, willows, and red alder. 



Climatic Conditions. — At north, climate extremely severe, with low atmospheric hu- 

 midity, small precipitation (sometimes not over 15 inches), great seasonal range of tem- 

 perature, and occasional strong, drying winds. Annual range of temperature, rarely less 



