Bark of a 35 cm dbh tree in the Seattle arboretum. Image width 15 cm [C.J. Earle]. |
Picea pungens
Engelmann 1879
Common NamesBlue spruce, Colorado blue spruce, white spruce, silver spruce, Parry spruce (1), épinette bleue (Canadian French), pino real (Spanish) (2).
Taxonomic notesSyn: Picea parryana Sargent. Limited hybridization occurs between Picea pungens and P. engelmannii (Daubenmire 1972; Taylor et al. 1975) (2).
DescriptionTrees to 50 m tall and 150 cm dbh; "crown broadly conic. Bark gray-brown. Branches slightly to strongly drooping; twigs not pendent, stout, yellow-brown, usually glabrous. Buds dark orange-brown, 6-12 mm, apex rounded to acute. Leaves 1.6-3 cm, 4-angled in cross section, rigid, blue-green, bearing stomates on all surfaces, apex spine-tipped. Seed cones [green or violet ripening pale buff], (5)6-11(12) cm; scales elliptic to diamond-shaped, widest below middle, 15-22 × 10-15 mm, rather stiff [at the base, with a thin flexible apex], margin at apex erose, apex extending 8-10 mm beyond seed-wing impression. 2 n =24" (2).
RangeUSA: Idaho, Wyoming, Utah, Colorado, New Mexico and Arizona at 1800-3000 m in midmontane forests (2). See also (5). USDA hardiness zone 4.
Big TreeHeight 37 m, dbh 150 cm, crown spread 11 m, located in Ashley National Forest, UT (4).
OldestMaximum ages of 600 years are cited in (3), without supporting data.
Dendrochronology
EthnobotanyThanks to its cold hardiness and glaucous foliage, which assumes a lurid blue hue in some cultivars, this is among the most widely planted ornamental spruces.
Observations
RemarksColorado blue spruce is the state tree of Colorado; blue spruce is the state tree of Utah (2).
Citations(1) Peattie 1950 .(2) Taylor, Ronald J. at the Flora of North America web site . (3) Burns & Honkala 1990 . (4) American Forests 1996 . (5) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html, accessed 22-Jan-2000.
See also
This page co-edited with Michael P. Frankis, Dec-1998. |
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