Trees to 25m (often shrublike); trunk to 0.25m diam.; 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. 3mm, 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; scales fan-shaped, broadest near apex, 8--12 ´ 8--12mm, rigid, margin at apex irregularly toothed. 2 n =24. Muskegs, bogs, bottomlands, dry peatlands; 0--1500m; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Conn., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Pa., R.I., Vt., Wis. 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 (A.G. Gordon 1976). Because Picea mariana is a small tree, it has limited commercial value. Frequently it is harvested with P . glauca and used for pulp.

Black spruce ( Picea mariana ) is the provincial tree of Newfoundland.