Picea pungens

Engelmann 1879

Common names

Blue spruce, Colorado blue spruce, white spruce, silver spruce, Parry spruce (Peattie 1950), épinette bleue (Canadian French), pino real (Spanish) (Taylor 1993).

Taxonomic notes

Syn: Picea parryana Sargent. Limited hybridization occurs between Picea pungens and P. engelmannii (Taylor 1993).

Description

Trees 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. 2n=24" (Taylor 1993).

Range

USA: Idaho, Wyoming, Utah, Colorado, New Mexico and Arizona at 1800-3000 m in midmontane forests (Taylor 1993). See also Thompson et al. (1999). USDA hardiness zone 4.

Big tree

Height 37 m, dbh 150 cm, crown spread 11 m, located in Ashley National Forest, UT (American Forests 1996). The tallest known tree grows in the San Juan Mountains of Colorado, and is 46.6 m tall and 106 cm dbh (Robert Van Pelt e-mail 2004.02.04).

Oldest

Maximum ages of 600 years are cited in Burns and Honkala (1990), without supporting data.

Dendrochronology

Ethnobotany

Thanks 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

The tallest tree known grows in Wolf Creek Campground below Wolf Creek Pass, near Pagosa Springs, Colorado; the whole area is thick with spectacular spruces, as are most riparian areas in the San Juan Mountains (Robert Van Pelt e-mail 2004.02.04).

Remarks

Colorado blue spruce is the state tree of Colorado; blue spruce is the state tree of Utah (Taylor 1993). Nobody has seen fit to name a spruce after Utah, but it does have a juniper.

Citations

This page co-edited with Michael P. Frankis, 1998.12.

See also

Farjon (1990).

FEIS database.

Lanner (1983).