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).

Distribution and Ecology

USA: Idaho, Wyoming, Utah, Colorado, New Mexico and Arizona at 1800-3000 m in midmontane forests (Taylor 1993). See also Thompson et al. (1999). Hardy to Zone 3 (cold hardiness limit between -39.9°C and -34.4°C) (Bannister and Neuner 2001).

Distribution data from USGS (1999). Points plotted as tree icons represent isolated or approximate locations.

Big tree

Height 37 m, dbh 150 cm, crown spread 11 m, located in Ashley National Forest, UT (American Forests 1996). The tallest known trees all grow in the San Juan Mountains of Colorado. The current height record, 48.5 m, belongs to a tree in the Hermosa Creek area, discovered in July 2012 by Bob Leverett (Leverett 2013). This tree has a dbh of only 61 cm and a crown spread of 11.0 m. The next-tallest specimen, 47.70 meters tall and 81 cm dbh, was found in 2009, also by Bob Leverett (Robert Van Pelt e-mail 2009.06.22).

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

Some of the tallest trees grow 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).

This species is widely distributed on the floor of Jackson Hole in Grand Teton National Park, particularly in riparian forests along the Snake River. Nearby, it seamlessly blends in with the ornamental cultivars of the same species that are planted on the lots of trophy homes around Jackson. It would be interesting to hunt out a few hybrids and see how they are doing.

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

Leverett, Robert T. 2013.04.27. Candidate for Picea pungens - Colorado blue spruce. www.ents-bbs.org/viewtopic.php?f=393&t=5328, accessed 2013.04.28.

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

See also

Farjon (1990).

FEIS database.

Lanner (1983).