"Reports of hybridization with J. pinchotii have been refuted by use of numerous chemical and morphologic characters; the two species have nonoverlapping pollination seasons" (Adams 1993).
"Shrubs or trees dioecious, to 7(12) m, usually branching near base; crown rounded to flattened-globose. Bark gray to brown, exfoliating in thin strips, that of small branchlets (5-10 mm diam.) smooth, that of larger branchlets exfoliating in either flakes or in strips. Branches ascending to erect; branchlets erect, 4-6-sided, ca. 2/3 as wide as length of scalelike leaves. Leaves green to dark green, abaxial glands elongate, fewer than 1/5 of glands (on whip leaves) with an evident white crystalline exudate, margins denticulate (at 20×); whip leaves 4-6 mm, glaucous adaxially; scalelike leaves 1-3 mm, not overlapping, or if so, by less than 1/4 their length, keeled, apex acute to acuminate, spreading. Seed cones maturing in 1 year, of 1 size, with straight peduncles, globose to ovoid, 6-8 mm, reddish blue to brownish blue, glaucous, fleshy and resinous, with 1(-3) seeds. Seeds 4-5 mm" (Adams 1993).
USA: Arizona, Colorado, New Mexico, Oklahoma and Texas at 1000-2300 m elevation on dry, rocky soils and slopes (Adams 1993). Other sources (Peattie 1950, Silba 1986) constrain the Texas range to the Panhandle, Big Bend and Edwards Plateau areas, and recognize an extension into Mexico (N Sonora and Chihuahua). See also Thompson et al. 1999. Hardy to Zone 4 (cold hardiness limit between -34.3°C and -28.9°C) (Bannister and Neuner 2001).
Diameter 136 cm, height 9 m, crown spread 9 m, located in the Jicarilla Mountains, NM (American Forests 1996).
Farjon (2005) provides a detailed account, with illustrations.
R.P. Adams' web site, juniperus.org.
Last Modified 2012-11-28