Pyramidal trees, with tall tapering trunks often stoutly buttressed at the base, thin scaly bark, soft pale wood containing numerous resin-canals, slender whorled twice or thrice ramified branches, their ultimate divisions stout, glabrous or pubescent, and leaf-buds usually in 3’s, the 2 lateral in the axils of upper leaves. Leaves linear, spirally disposed, extending out from the branch on all sides or occasionally appearing 2-ranked by the twisting of those on its lower side, mostly pointing to the end of the branch, entire, articulate on prominent persistent rhomboid ultimately woody bases, keeled above and below, 4-sided and stomatiferous on the 4 sides, or flattened and stomatiferous on the upper and occasionally on the lower side, persistent from seven to ten years, deciduous in drying. Flowers terminal or in the axils of upper leaves, the male usually long-stalked, composed of numerous spirally arranged anthers with connectives produced into broad nearly circular toothed crests, the female oblong, oval or cylindric, with rounded or pointed scales, each in the axis of an accrescent bract shorter than the scale at maturity. Fruit an ovoid or oblong, cylindric pendant cone, crowded on the upper branches or in some species scattered over the upper half of the tree. Seeds ovoid or oblong, usually acute at base, much shorter than their wings; outer seed-coat crustaceous, light or dark brown, the inner membranaceous, pale chestnut-brown; cotyledons 4—15. Picea is widely distributed through the colder and temperate regions of the northern hemisphere, some species forming great forests on plains and high mountain slopes. Thirty-seven species are now recognized, ranging from the Arctic Circle to the slopes of the southern Appalachian Mountains and to those of northern New Mexico and Arizona in the New World, and to central and southeastern Europe, the Caucasus, the Himalayas, western China, Formosa and Japan. Of exotic species the so-called Norway Spruce, _Picea Abies_ Karst., one of the most valuable timber-trees of Europe, has been largely planted for ornament and shelter in the eastern states, where the Caucasian _Picea orientalis_ Carr., and some of the Japanese species also flourish. _Picea_ was probably the classical name of the Spruce-tree. CONSPECTUS OF THE NORTH AMERICAN SPECIES.