Juniperus coahuilensis

(Martinez) Gaussen ex R.P. Adams 1993

Common names

Roseberry juniper (Adams 1993), redberry juniper.

Taxonomic notes

There are two varieties: Juniperus coahuilensis var. coahuilensis (syn. J. erythrocarpa Cory var. coahuilensis Martinez 1946), and Juniperus coahuilensis var. arizonica R.P. Adams 1994 (Farjon 2005).

"Hybridization with Juniperus pinchotii occurs in Big Bend National Park, Texas (Adams and Kistler 1991), and possibly near Saltillo, Mexico. Reports of hybridization with J. ashei have been refuted (Adams 1975)" (Adams 1993).

Description

"Shrubs or trees dioecious, to 8 m, single-stemmed to 1 m or branched at base; crown flattened-globose to irregular to round. Bark gray to brown, exfoliating in long ragged strips, that of small branchlets (5-10 mm diam.) smooth, that of larger branchlets exfoliating in strips, or occasionally in flakes. Branches spreading to ascending; branchlets erect, 3-4-sided in cross section, ca. 2/3 as wide as length of scalelike leaves. Leaves green to light green, abaxial glands elliptic to ovate, at least 1/4 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, spreading. Seed cones maturing in 1 year, of 1 size, with straight peduncles, globose to ovoid, 6-7 mm, rose to pinkish but yellow-orange, orange, or dark red beneath glaucous coating, fleshy and somewhat sweet, with 1(-2) seeds. Seeds 4-5 mm" (Adams 1993).

Range

Var. coahuilensis occurs in Mexico: Coahuila and USA: Texas (Farjon 2005). Var. arizonica occurs in USA: Arizona, New Mexico, and Texas, at 980-1600(-2200) m elevation on Bouteloua grasslands and adjacent rocky slopes (Adams 1993). In Arizona it occurs with J. osteosperma on some sites, or with Opuntia spp. or Yucca spp., but commonly its only associates are grasses, an unusual setting for a conifer. Its persistence in grasslands may be due to its unusual ability to resprout from cut or fire-killed stumps (Farjon 2005, citing pers. comm. from R.P. Adams).

Big tree

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

See also

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

R.P. Adams' web site, juniperus.org.