Juniperus deppeana description

Juniperus deppeana Steudel 1841

Common Names

Alligator juniper, cedro chino (2), mountain, thickbark, oak-barked, or checker-barked cedar (3).

Taxonomic notes

Syn: J. patoniana (1). Five varieties according to (4); the type var. deppeana described here, and pachyphlaea .

"Although four additional varieties are found in Mexico, the relationships among the J. deppeana taxa are poorly understood and need additional study (Adams et al. 1984). The very rare J. deppeana Steudel var. deppeana forma sperryi (Correll) R. M. Adams (= J. deppeana Steudel var. sperryi Correll) is endemic to the Davis Mountains, Texas, where only two or three individuals are known to exist. This form is characterized by bark that exfoliates in thin strips and by flaccid branchlets" (4).

Description

"Trees dioecious, to 10-15(-30) m, single-stemmed; crown rounded. Bark brown, exfoliating in rectangular plates (rarely in thin strips in f. sperryi , but then branchlets flaccid), that of small branchlets (5-10 mm diam.) smooth, that of larger branchlets exfoliating in plates. Branches spreading to ascending; branchlets erect, rarely flaccid, 3-4-sided in cross section, ca. 2/3 or less as wide as length of scalelike leaves. Leaves green, but sometimes appearing silvery when glaucous, abaxial gland ovate to elliptic, conspicuous, exudate absent, margins denticulate (at 20´); whip leaves 3-6 mm, not glaucous adaxially; scalelike leaves 1-2 mm, not overlapping, keeled, apex acute to mucronate, appressed. Seed cones maturing in 2 years, of 2 distinct sizes, with straight to curved peduncle, globose, 8-15 mm, reddish tan to dark reddish brown, glaucous, fibrous to obscurely woody, with (3-)4-5(-6) seeds. Seeds 6-9 mm" (4).

Range

USA: mountains of C & SE Arizona, C & SW New Mexico, W Texas; and Mexico: Sonora, Chihuahua and Coahuila (3), at 2000-2900 m (4). See also (5). Var. pachyphlaea from Arizona to W Texas and Sonora (1).

Big Tree

Diameter 265 cm, height 14 m, crown spread 15 m, located on Granite Mountain, Prescott National Forest, AZ ( American Forests 1996 ).

Oldest

Dendrochronology

Ethnobotany

Observations

Seen often in mountains of SE Arizona.

Remarks

Citations

(1) Silba 1986 .

(2) Elmore & Janish 1976 .

(3) Peattie 1950 .

(4) Adams, Robert P. in Flora of North America online .

(5) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html , accessed 22-Jan-2000.