Trees evergreen; trunk monopodial, straight; branches nearly whorled; branchlets ridged and grooved, with each leaf borne on a persistent, peglike base (pulvinus); short branchlets absent; winter buds ovoid, conical, or subglobose, resinous or not, scales on terminal buds recurved or not, persistent at base of branchlets. Leaves spirally arranged, spreading radially, or directed forward on upper side of branchlets and spreading on lower side, each inserted on a petiolelike pulvinus, linear, straight or curved, quadrangular, broadly rhombic, or flattened in cross section, stomatal lines adaxial or on each surface, vascular bundle 1, resin canals 2, sometimes small and discontinuous. Pollen cones solitary in leaf axils, rarely terminal, ellipsoid or cylindric; pollen 2-saccate. Seed cones solitary, pendulous at maturity, ovoid-cylindric or cylindric, rarely ovoid, maturing in 1st year. Seed scales thinly woody, leathery, or papery, with margin entire, denticulate, or undulate toward apex, persistent. Bracts included, small. Seeds obovoid or ovoid; wing long, membranous. Cotyledons 4-9(-15). Germination epigeal. 2n = 24*.
Trees evergreen; crown broadly conic to spirelike; leading shoot erect. Bark gray to reddish brown, thin and scaly (with thin plates), sometimes with resin blisters (especially in Picea engelmannii and P . glauca ), becoming relatively thick and furrowed with age. Branches whorled; short (spur) shoots absent; twigs roughened by persistent leaf bases. Buds ovoid, apex rounded to acute, sometimes resinous. Leaves borne singly, spreading in all directions from twigs, persisting to 10 years, mostly 4-angled and square in cross section (to triangular or ± flattened), mostly rigid, sessile on peglike base; base decurrent, persistent after leaves shed, sheath absent; apex usually sharp-pointed, sometimes bluntly acute; resin canals 1--2. Cones borne on year-old twigs. Pollen cones grouped, axillary, oblong, yellow to purple. Seed cones maturing in 1 season, usually shed at maturity (persisting for several years in Picea mariana ), borne mostly on upper branches, pendent, ovoid to cylindric, sessile or terminal on leafy branchlets and thus appearing ± stalked; scales persistent, elliptic to fan-shaped, thin, lacking apophysis and umbo; bracts included. Seeds winged; cotyledons 5--l5. x =12.
"Male and female cones terminating twigs of the previous year’s growth; female cones pendulous, with persistent scales much exceeding the bracts; evergreen trees, the quadrangular lvs jointed at the base to a short, projecting sterigma that persists on the denuded branch; resin-ducts 2 in each lf; 2n=24. 30+, N. Temp"
Roche, L. 1969. A genecological study of the genus Picea and seedlings grown in a nursery. New Phytol. 68: 505--554. Taylor, R.J. and T.F. Patterson. 1980. Biosystematics of Mexican spruce species and populations. Taxon 29: 421--469. Wright, J.W. 1955. Species crossability in spruce in relation to distribution and taxonomy. Forest Sci. 1: 319--349.
|Spruce, épinette [Latin picis, pitch, name of a pitchy pine]|