Picea mariana var. semiprostrata (Peck) Teeri
Synonym: Picea mariana forma semiprostrata (Peck) Blake
General: Trees to 25 meters tall (often shrub-like near tree-line), the crown narrowly conic to spire-like or “irregularly subcylindric;” branches short and drooping, frequently layering; twigs not pendent, slender, yellow-brown, hairy; bark gray-brown. Needles evergreen, 0.6-1.5(-2) cm long, 4-angled, stiff and blunt-tipped, waxy and pale blue-green. Seed cones 1.5-2.5(-3.5) cm long, fusiform, purple-brown at maturity; cone scales fan-shaped, broadest near apex, 8-12 mm long, rigid, margin at apex irregularly toothed. Native. The common name refers to the dark (blackish) foliage.
Variation within the species: Black spruce shows north-south clinal variation in photoperiodism, productivity, and other traits, and discrete variants are not recognized at present, except for one. Fernald (1950) recognized “depressed” and “trailing” alpine forms at the rank of forma, but Roland and Smith (1969) and Rouleau and Lamoureux (1992) have treated them as var. semiprostrata. These occur in Keewatin, Quebec, Newfoundland, and Nova Scotia:
However, these are of little significance to NRCS and conservation personnel in the United States.
Black spruce hybridizes with red spruce (Picea rubens) on disturbed sites in eastern Canada and with white spruce in a few places. Reports of natural hybrids between black spruce and white spruce apparently remain unverified.
Distribution: Black spruce occurs across the northern range of North America, from Alaska, Yukon, and British Columbia eastward to Nova Scotia, Newfoundland, New Brunswick, and Québec. It also occurs in the northeastern United States and sporadically in Minnesota, Wisconsin, and Michigan. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.