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Tree in habitat, Sedona, AZ [C.J. Earle, 1987.12.27].

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A stand in southern Puebla [C.J. Earle, 2005.02.10].

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Bark on the tree shown above, about 50 cm dbh [C.J. Earle, 2005.02.10].

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The largest known specimen of f. sperryi, with R.P. Adams [D. Thornburg, ca. 2010].

 

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Conservation status

Juniperus deppeana var. deppeana

Steudel 1841

Common names

Alligator juniper (Elmore and Janish 1976), mountain, thickbark, oak-barked, or checker-barked cedar (Peattie 1950), cedro, cedro chino [in Puebla], tláscal or tláxcal [in Hidalgo] (Zanoni and Adams 1979).

Taxonomic notes

Includes three formae (Adams and Schwarzbach 2006):

Description

For the type variety: dioecious trees 10-15(-30) m tall, single-stemmed. Crown rounded. Bark brown, exfoliating in rectangular plates, 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 (with a 20X hand lens); 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 in diameter, red-tan to dark red-brown, glaucous, fibrous to obscurely woody, with (3-)4-5(-6) seeds. Seeds 6-9 mm (Adams 1993).

J. deppeana Steudel var. deppeana forma elongata has long (15-30 cm) terminal whip branchlets and nearly all leaves on adult plants are juvenile (decurrent acicular) rather than scale leaves (Adams and Schwarzbach 2006).

J. deppeana Steudel var. deppeana forma sperryi has bark that exfoliates in thin strips, and flaccid branchlets (Adams 1993).

J. deppeana Steudel var. deppeana forma zacatecensis differs from the type variety in having larger (10-20 mm diameter) seed cones with a heavy bloom (waxy coating) (Adams and Schwarzbach 2006).

Distribution and Ecology

USA: mountains of C and SE Arizona, C and SW New Mexico, W Texas; and Mexico: Aguascalientes, Coahuila, Durango, Hidalgo, México, Nuevo León, Puebla, San Luis Potosí, Sonora, Tamaulipas, Tlaxcala, Veracruz, and Zacatecas at 1500-2900 m (Zanoni and Adams 1979, Adams 1993). See also Thompson et al. 1999.

J. deppeana Steudel var. deppeana forma elongata occurs only as scattered trees in the Davis Mountains, Texas (Adams and Schwarzbach 2006).

J. deppeana Steudel var. deppeana forma sperryi is endemic to the Davis Mountains, Texas, where only two or three individuals are known to exist (Adams 1993). Its conservation status is "critically endangered" (IUCN 2008).

J. deppeana Steudel var. deppeana forma zacatecensis occurs in oak-pine-juniper and piñon-juniper woodlands, and on grasslands, at 1980-2470 m elevation in Zacatecas and adjacent Durango and Aguascalientes (Adams and Schwarzbach 2006). Its conservation status is "vulnerable" (IUCN 2008).

Big tree

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

Oldest

Dendrochronology

Ethnobotany

Observations

Can easily be seen in foothills of the mountains of SE Arizona, e.g. the Chiricahua, Dragoon, Santa Rosa, Rincon and Santa Catalina Mountains. Also reasonably common within its range in Mexico. I have not seen the formae, though.

Remarks

Citations

See also

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

The Vascular Plant Image Gallery.

Last Modified 2012-11-23