Picea mariana description

Foliage on a young sapling on the slopes of Mt. Katahdin, Maine. Note short needles, pale green new foliage [C.J. Earle, Jul-2004].

Cones on a tree in a recently-burned muskeg, central Alaska [C.J. Earle, Jul-1991].

Bark on a tree in Maine, about 25 cm diameter [C.J. Earle, 14-Jul-2003].

Distribution map (USGS 1999.

River in Alaska bordered by P. glauca forests surrounded by muskeg containing scattered small P. mariana [Dr. Linda B. Brubaker].

Picea mariana (Miller) Britton Sterns, & Poggenburg 1888

Common Names

Black spruce, bog spruce, swamp spruce, épinette noire (Canadian French) (Taylor 1993).

Taxonomic notes

Syn: Abies mariana Miller 1768; Picea brevifolia Peck; P. mariana var. brevifolia (Peck) Rehder; P. nigra (Aiton) Link; Pinus nigra Aiton (Taylor 1993).

"To a limited extent, Picea mariana hybridizes with P. rubens, e.g., on disturbed sites in eastern Canada. Natural hybridization with P. glauca, though reported, remains unverified" (Taylor 1993).

Description

Trees to 25 m tall and 25 cm dbh (often much smaller, occurring as krummholz near the arctic treeline); "crown narrowly conic to spirelike. Bark gray-brown. Branches short and drooping, frequently layering; twigs not pendent, rather slender, yellow-brown, pubescent. Buds gray-brown, ca. 3 mm, apex acute. Leaves 0.6-1.5(2) cm, 4-angled in cross section, rigid, pale blue-green, glaucous, bearing stomates on all surfaces, apex mostly blunt-tipped. Seed cones 1.5-2.5(-3.5) cm [in cultivation rarely to 4.5 cm]; scales fan-shaped, broadest near apex, 8-12 × 8-12 mm, rigid, margin at apex irregularly toothed. 2n=24" (Taylor 1993). Cones fusiform, matt, dark purple ripening purple-brown (c.f. P. rubens ovoid, glossy, orange-brown).

Range

Canada: all provinces; France: St. Pierre and Miquelon; USA: Alaska, Minnesota, Wisconsin, Michigan, Pennsylvania, New York, New Jersey, Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire and Maine at 0-1500 m in muskegs, bogs, bottomlands, and relatively dry peatlands (Taylor 1993). See also Thompson et al. (1999). USDA hardiness zone 2.

Big Tree

Height 24 m, dbh 50 cm, crown spread 6 m, located in Taylor County, WI (American Forests 1996). Vladimir Dinets (e-mail, 18-Oct-2003) reports "some unusually tall stands can be seen in eastern Labrador. I measured (by shadow comparison) a tree near Muskrat Falls (Goose Bay area) to be appr. 30 m tall."

Oldest

A crossdated age of 330 years was recently secured for a tree in Sleeping Giant Provincial Park, Ontario (Girardin et al. 2006).

Dendrochronology

Ethnobotany

Although it is a small tree, vast tracts of it are currently being logged in Canada, primarily for pulp but also for timber (for example, the chopsticks provided at fast-food restaurants in the Far East are usually P. mariana).

Observations

Readily encountered in its native habitat throughout Canada, Alaska, and northern Minnesota, Wisconsin, Michigan and Maine. I was particularly interested by its occurrence near the summit of Mt. Katahdin in Maine, where it forms an alpine krummholz shrub, with trees only a few decimeters tall bearing cones. This is the only place I have seen it form alpine (rather than arctic) krummholz.

Remarks

Black spruce is the provincial tree of Newfoundland (Taylor 1993).

Citations

Girardin, M.-P., J.C. Tardif, M.D. Flannigan and Y. Bergeron. 2006. Synoptic-Scale Atmospheric Circulation and Boreal Canada Summer Drought Variability of the Past Three Centuries. Journal of Climate 19(10):1922-1947.