White Spruce

(Picea glauca)

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White Spruce (Picea glauca)

Identifying Characters: White Spruce is characterized by its boreal distribution and the slender, cylindrical cones. The cone scales are flexible and the apices are rounded or truncate.

Similar Species: White Spruce is readily separated the other two eastern spruce species (Black and Red Spruces) by its elongate cones and flexible cones scales. White Spruce occurs with Sitka Spruce in the west. The cone scales of White Spruce are rounded are truncate, but those of Sitka Spruce are usually more elongate and pointed. The cones of Sitka Spruce are longer (2.5 to 4 inches) than those of White Spruce (1 to. 2.5 inches). The needles of White Spruce are diamond-shaped in cross section, but those of Sitka Spruce are much flatter. White Spruce may be confused with the commonly planted ornamental Norway Spruce. The Norway Spruce is not a native conifer and the cones are much larger and longer (4 to7 inches) than those of White Spruce.

Measurements: Mature trees grow up to 75 feet tall and 2 feet in diameter. There is wide variation in measurements under different habitat types.

Cones: Cones 1 to 2.5 inches long, averaging 2 inches in length; cones nearly sessile with branch, elongate, cylindric, slender; cone scales; color light green becoming tinged with red when mature; cone scale apex rounded to truncate, sometimes slightly emarginate.

Needles: Needles concentrated on upper side of the branches; needles about 1 inch in length, dark green to blue-green in color; needles diamond-shaped in cross section.

Bark: Bark light gray slightly tinged with brown; bark 1/4 to 1/2 inches thick and broken irregularly into plate-like scales.

Native Range: White Spruce has a transcontinental range, from Newfoundland and Labrador west across Canada along the northern limit of trees to Hudson Bay, Northwest Territories, and Yukon. It almost reaches the Arctic Ocean at latitude 69° N. in the District of Mackenzie in the Northwest Territories . In Alaska, it reaches the Bering Sea at Norton Bay and the Gulf of Alaska at Cook Inlet. In British Columbia, it comes within 100 km (60 mi) of the Pacific Ocean in the Skeena Valley where it overlaps with Sitka spruce (Picea sitchensis), and from there it extends south through British Columbia, and east through Alberta and Manitoba to Lake Winnipeg and south and east through northern Minnesota and Wisconsin, central Michigan, northeastern New York, and Maine. The contiguous distribution shown extending south in the Rocky Mountains into Montana actually may be outliers similar to those found further south in Montana, in the Black Hills in Wyoming and South Dakota (approximately latitude 44° N.), and at Cypress Hills in Saskatchewan. White spruce grows from sea level to about 1520 m (5,000 ft) elevation. It is found near 610 m (2,000 ft) on the central tableland of Labrador north of latitude 52° N. (108), and in Alaska white spruce forests approach 910 m (3,000 ft) at about latitude 68° N. in the Dietrich River Valley on the south slope of the Brooks Range. It reaches 1160 m (3,800 ft) in the timberline forest at latitude 61° N. in the Liard Range in the Northwest Territories, and farther south in the Rocky Mountains it is the dominant species from the edge of the plains at 1220 m (4,000 ft) to about 1520 m (5,000 ft). In interior British Columbia, white spruce grows at elevations as low as 760 m (2,500 ft) in the east Kootenay Valley. (Silvics of North America. 1990. Agriculture Handbook 654.)

Habitat: White Spruce is a very plastic species occurring in a wide variety of habitats and soil conditions within its boreal range. In the west the species is most common along rivers and lake shores.