Trees to 40m; trunk to 1m diam.; crown narrowly conic. Bark gray-brown to reddish brown. Branches horizontally spreading; twigs not pendent, rather stout, yellow-brown, densely pubescent to glabrate. Buds reddish brown, 5--8mm, apex acute. Leaves 0.8--2.5(--3)cm, 4-angled in cross section, somewhat flexuous, yellow-green to dark green, not glaucous, bearing stomates on all surfaces, apex mostly acute to sharp-pointed. Seed cones 2.3--4.5(--5)cm; scales broadly fan-shaped, broadest near apex, 8--12 ´ 8--12mm, stiff, margin at apex entire to irregularly toothed. 2 n =24. Upper montane to subalpine forests; 0--2000m; St. Pierre and Miquelon; N.B., N.S., Ont., P.E.I., Que.; Conn., Maine, Md., Mass., N.H., N.J., N.Y., N.C., Pa., Tenn., Vt., Va., W.Va. Throughout the Appalachians, trees of Picea rubens are dying, possibly as a consequence of environmental pollution. In eastern Canada this species hybridizes to a limited extent with P . mariana (A.G. Gordon 1976). Red spruce ( Picea rubens ) is the provincial tree of Nova Scotia.
Tree to 30 m, with a relatively broad and pyramidal or conic crown, the branches longer than in no. 2 [Picea mariana (Mill.) Britton, Sterns & Poggenb.] and tending to be horizontally spreading, with upturned tip; twigs pubescent as in no. 2, but the hairs more steeple-shaped; lvs 10-30 mm, sharply pointed, shiny yellow-green, not glaucous, those on the upper side forwardly ascending or erect, the others all laterally ascending-spreading or tending to be upcurved, those on the lower side twisted at the base; winter buds acute, chestnut-brown, the lowest scales pubescent and subulate; cones green or purplish-green before maturity, brown or reddish-brown when ripe, oblong-ovoid, 3-4.5 cm, mostly falling the first winter after maturity, more fragile than in no. 2, the cone-scales easily detached from the axis, but with firmer, more rounded, often entire margin. Rocky woods and hillsides, esp. in the mts.; Que. and Ont. to Pa. and N.J., and s. in the higher mts. to N.C. and Tenn. (P. australis; P. rubra) Hybridizes extensively with no. 2.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.