28 BULLETIN 1485, U. S. DEPARTMENT OF AGRICULTURE 
Sitka Spruce {Picea sitchensis) 
Other names in use. — Tideland spruce and western spruce. Trade names of 
the lumber are Sitka spruce, yellow spruce, silver spruce, and west coast spruce. 
Range. — Pacific coast region (extending inland about 50 miles) from the east 
end of Kadiak Island and Alaska to northern California. 
Oven-dry weight per cubic foot, green volume. — 24 pounds. 
Fiber length. — 3.5 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Strong and of excellent color, texture not quite so fine as 
that of white spruce; bleaches easily to excellent white. 
Yields : 45 to 50 per cent. 
Bleach required: 10 to 20 per cent. 
Uses to which pulp is suited: News, wrapping, book, high-grade printing, and 
bond papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp: Strong, of fairly fine texture. 
Yields: 45 to 50 per cent of strong pulp, 38 to 43 per cent of pulp for bleaching. 
Bleach required: 20 to 30 per cent in one stage, or 15 to 20 per cent in two 
stages. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
By Mechanical Process 
Reduces readily. 
Pulp: Slightly grayish in color and of standard strength. 
Power required: Comparable to that for white spruce. 
Uses to which pulp is suited: Practically all uses requiring ground wood. 
White Spruce (Picea glauca, formerly, P. canadensis) 
Other names in use. — Single spruce, cat spruce, skunk spruce, and blue spruce. 
The lumber, mixed with that of red spruce, is sold as eastern spruce. 
Range. — Labrador to Hudson Bay and northwestward through Alaska to Bering 
Strait; southward in the Atlantic region to Maine, New Hampshire, Vermont, 
northern New York, Michigan, Wisconsin, and Minnesota. 
Oven-dry weight per cubic foot, green volume. — 24 pounds. 
Fiber length. — 2.8 mm. 
By Sulphite Process 
Reduces readily. 
Unbleached pulp: Strong, of fine texture and excellent color, although occa- 
sionally somewhat pitchy; bleaches easily to excellent white. 
Yields: 45 to 50 per cent. 
Bleach required: 10 to 20 per cent. 
Uses to which pulp is suited: News, wrapping, book, high-grade printing, 
and bond papers. 
By Sulphate Process 
Reduces readily. 
Unbleached pulp : Very strong, of fine texture. 
Yields: 45 to 50 per cent of strong pulp, 38 to 43 per cent of pulp for bleaching. 
Bleach required: 20 to 30 per cent in one stage, or 15 to 20 per cent in two 
stages. 
Uses to which pulp is suited: High-grade kraft wrapping papers and fiber 
board. 
By Mechanical Process 
Reduces readily. 
Pulp: Of excellent color and standard strength. 
Power required: 60 to 80 horsepower-days per ton (in actual commercial 
practice) . 
Uses to which pulp is suited: Practically all uses requiring ground wood. 
