A tree 20 to 30 ft (occasionally twice or thrice as) high, of close, pyramidal habit as seen in cultivation, branches densely twiggy; young shoots abundantly furnished with reddish down; terminal bud with a few downy awl-shaped scales at the base. Leaves arranged all round the twig, but thinly beneath, 1⁄4 to 5⁄8 in. long, slightly curved, quadrangular, with a bluntish, bevelled point; more or less glaucous in hue, with two to five lines of stomata on each surface. Cones egg-shaped, 3⁄4 to 11⁄4 in. long, brownish purple when young; scales rounded or somewhat bluntly triangular at the apex, and slightly jagged at the margin.
Native of N. America, where it covers an immense tract from Labrador and Alaska in the north to Virginia and Wisconsin in the south; introduced to the Fulham garden about 1700 by Bishop Compton. This is not one of the most ornamental of spruces, but is still pleasing in its dense furnishing of leaves and its large crops of rich purple young cones. It is nearly allied to P. rubens, but differs in its blue-green foliage and in the long persistence of its cones upon the branches – twenty to thirty years, according to Sargent.
Among the few specimens of the black spruce in this country are: Nymans, Sussex, 63 × 53⁄4 ft (1970), and another of about the same size; Wakehurst Place, Sussex, 53 × 4 ft (1964); Rhinefield Drive, Hants., 69 × 41⁄2 ft (1971); Caerhays Castle, Cornwall, 62 × 63⁄4 ft (1971).
cv. ‘Doumetii’. – A small densely branched tree growing slowly to about 10 ft in this country. Leaves blue-green, slender, crowded, mostly under 1⁄2 in. long. Branchlets bright orange-brown. This variety was described by Carrière in 1855 from a plant growing at the Château de Balaine near Moulins, where there was (and still is) a fine collection of American trees planted by Aglaé Adanson, daughter of the French botanist Michel Adanson (1727-1806). The original tree was planted about 1835; when Elwes visited La Balaine early this century it was dead, but still standing and about 30 ft high.
cv. ‘Ericoides’ . – This is a pigmy form of the black spruce, and is a rounded bush with very slender leaves never more than 3⁄8 in. long, almost heathlike, young shoots thin, much branched, downy the first two or three years. It has been known since the second half of the last century but is extremely rare and is only mentioned here because the earliest description of it appeared in the first edition of this work.