Description
Picea pungens is a medium to large tree, growing up to 40 or sometimes 50 m tall, with a trunk that grows up to around 1.5 m in diameter. It forms a dense conical crown; the main branches radiate smaller side branches from all directions, with some small branches growing directly from the trunk. Needles are stiff, curved somewhat forward, around 1.5 to 3 cm long, square in cross section with a very sharp tip. They are grayish or bluish green with three to six pale bands (which are stomata) on all sides of the needles. As with other species in the genus Picea, the needles are attached to the twig via a woody "peg" that persists after the needle has fallen. Buds are 5 to 12 mm long, not resinous. The bark is grayish and scaly. Twigs are yellowish brown when new and are hairless. Pollen cones are around 2 to 3 cm, red. Seed cones are around 7 to 10 cm long, hanging down from the branchlets. They are green, ripening to a light brown. The cone scales are diamond-shaped but with the tip truncated and irregularly toothed, thin and flexible. The seeds are 3 to 5 mm long, with a wing that is 5 to 7 mm long (Eckenwalder 2009).
Picea pungens is similar to, and can coexist with Engelmann’s spruce (Picea engelmannii), but generally does not hybridize (Eckenwalder 2009). Compared to this species, P. engelmannii has smaller cones and less prickly needles (Kershner et al. 2008).
Uses
Note: Please see the disclaimer regarding any information about medical or edible uses.
The wood of Picea pungens is brittle and therefore not very useful, but Picea pungens is commonly cultivated as an ornamental, due to its symmetrical form and attractive blue color. Many trees in the wild are not exceptionally colored, but the cultivars, having been selectively bred, are vibrantly blue. Dwarf forms of the species are also available (Farjon 2013). It grows well in acidic, well-drained soils, medium moisture (but tolerating some drought), and full sun. It prefers cooler climates and does not like hot summers; it grows in USDA zones 2 to 7 (MBG).
Distribution
Picea pungens typically grows on gravelly sites, often near streams, on mountains at elevations between 1800 and 3300 m. It is native to the Rocky Mountains, and is most common in Wyoming, Colorado, Utah, and southern Idaho; there are also scattered populations in New Mexico and Arizona (Farjon 2013). Due to its frequent cultivation, it has become naturalized in many places, notably the northeastern United States, Europe, and Uzbekistan (Hassler 2022).
Status
Picea pungens is listed on the IUCN Red List as “Least Concern”. Although populations can be small and isolated, the overall population is large and there are no significant threats to the species (Farjon 2013).
References
Eckenwalder, J. E. 2009. <i>Conifers of the world: the complete reference</i>. Portland: Timber Press.<br><br>Farjon, A. 2013. <i>Picea pungens</i>. <i>The IUCN Red List of Threatened Species</i>. <a>https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T42333A2973433.en</a>.<br><br>Hassler, M. 2022. World Plants. Synonymic Checklist and Distribution of the World Flora. Version 14.0; last update 2022 August 2. [accessed 2022 Aug 27]. <a>www.worldplants.de</a><br><br>Kershner, B., Tufts, C., Nelson, G., Spellenberg, R., Purinton, T., Block, R., Moore, G., and Thieret, J. W. 2008. <i>National Wildlife Federation: Field Guide to Trees of North America</i>. New York: Sterling Publishing Company.<br><br>MBG (Missouri Botanical Garden). Picea pungens. <i>Plant Finder</i>. [accessed 2022 Aug 28]. <a>http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=284991</a>.<br><br>State of Colorado. 2022. Symbols and Emblems. <i>Colorado State Archives</i>. [accessed 2022 Aug 27]. <a>https://archives.colorado.gov/collections/symbols-emblems</a>.
