The Gymnosperm Database

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Tree in habitat, Davis Mountains, Texas [Jeff Bisbee, 2014.09].

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Cones and foliage on a tree north of Del Rio, Texas [Jeff Bisbee, 2014.09].

 

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Conservation status

Juniperus pinchotii

Sudworth 1905

Common names

Pinchot juniper, redberry juniper (Adams 1993).

Taxonomic notes

Syn: Juniperus erythrocarpa Cory (Adams 1993).

Adams (1993) observes that the "type specimen of J. erythrocarpa is merely an individual with brighter red seed cones." J. pinchotii and J. coahuilensis hybridize, but J. pinchotii does not hybridize with J. ashei or J. monosperma (Adams 1993).

Description

Dioecious shrubs or small trees up to 6 m tall, usually multistemmed with stems to 20 cm diameter, having an irregular crown. Bark smooth, becoming flaky, becoming fibrous, pale gray, exfoliating in strips. Branchlets stiff, about 1 mm diameter, erect, 3-4-sided in cross section. Bears both needles-like and scale-like leaves, but the scale-like leaves predominate; they are yellow-green, 1-2 mm long, not overlapping or overlap only slightly, and have an acute apex; many bear ruptured glands that emit an aromatic white exudate. Seed cones maturing in 1 year, 6-8 mm diameter, copper to copper-red in color, juicy, sweet (not resinous), mostly with a single seed 4-5 mm in diameter (Adams 2008).

Distribution and Ecology

US: New Mexico, Oklahoma, and Texas; Mexico: Coahuila and Nuevo León; at 300-1000(-1700) m elevation; on gravelly limestone and gypsum soils; on rolling hills and in ravines (Adams 1993, 2008). Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (Bannister and Neuner 2001). See also Thompson et al. (1999).

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

Commonly occurs in association with honey mesquite (Prosopis glandulosa) or shrub live oak (Quercus turbinella), and is successional to it. The seeds can survive ground fire and the plants can resprout after cutting or fire. It does not compete effectively with bunch grasses, however, and frequent fire favors development of grassland, while fire suppression leads to development of juniper woodland (Hauser 2007 and numerous citations therein). Grazing pressure, by reducing competition from bunchgrasses, also favors juniper development (McPherson and Wright 1990). As a consequence, ranchers now regard this species as a weed.

Big tree

Diameter 115 cm, height 7 m, crown spread 8 m, located in Alpine, TX (American Forests 1996).

Oldest

Ages to 175 years have been reported from isolated buttes in Garza County, Texas (Ellis and Schuster 1968, Mullins and Mitchell 1996).

Dendrochronology

Ethnobotany

Observations

Remarks

Unlike most species in the Cupressaceae, the wood is not rot-resistant (Adams 2008).

Citations

Adams, Robert P. 1993. Juniperus. Flora of North America Editorial Committee (eds.): Flora of North America North of Mexico, Vol. 2. Oxford University Press. This document is available online. Go to http://www.efloras.org, click on "Flora of North America," and search for "Juniperus."

Adams, Robert P. 2008. Junipers of the World: The Genus Juniperus. Second edition. Trafford Publishing. Brief versions of the descriptions are available online at Adam's website, www.juniperus.org.

American Forests 1996. The 1996-1997 National Register of Big Trees. Washington, DC: American Forests. This is a dated citation; the big tree register is now available online.

Ellis, Dalton, and Joseph L. Schuster. 1968. Juniper age and distribution on an isolated butte in Garza County, Texas. The Southwestern Naturalist 13(3):343-348.

Hauser, A. Scott. 2007. Juniperus pinchotii. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Available: http://www.fs.fed.us/database/feis/, accessed 2009.11.29.

McPherson, G. R. and H. A. Wright. 1990. Effects of cattle grazing and Juniperus pinchotii canopy cover on herb cover and production in western Texas. American Midland Naturalist 123:144-151.

Mullins, Susan J., and Robert B. Mitchell. 1996. Management and ecology of redberry juniper on the Texas Rolling Plains. P. 12 in C. M. Britton and D. B. Wester (eds.), Research highlights 1996: Noxious brush and weed control; range and wildlife management. Volume 27. Lubbock, TX: Texas Tech University, College of Agricultural Sciences and Natural Resources.

See also

Farjon (2005) provides a detailed account, with illustrations.

Little (1980).

McPherson, G. R. and H. A. Wright. 1987. Factors affecting reproductive maturity of redberry juniper (Juniperus pinchotii). Forest Ecology and Management 21:191-196.

McPherson, G. R. and H. A. Wright. 1989. Direct effects of competition on individual Juniperus pinchotii plants: a field study. Journal of Applied Ecology 26:979-988.

Last Modified 2017-12-29