J. monticola growing prostrate in mats about 8 m across, with Pinus hartwegii, at the alpine timberline on Nevado de Colima; elevation approximately 3,800 m [C.J. Earle, 2005.02.14].
J. monticola f. compacta growing on rock outcrop with Pinus hartwegii, above the alpine timberline on Nevado de Toluca; elevation approximately 4,200 m [R. Van Pelt, 2005.02.12].
Berries and scale foliage on a female plant near Las Crucitas, Nuevo León [Jeff Bisbee, 2014.09].
Juniperus monticola
Cedro, sabino, sabino de castillo (Pico de Orizaba, Veracruz), tlascal (Hidalgo); mountain juniper (Adams 2004).
Three formae:
Synonymy for Juniperus monticola f. monticola (Adams 2004):
Synonymy for Juniperus monticola f. compacta (Adams 2004):
Synonymy for Juniperus monticola f. orizabensis (Adams 2004):
Dioecious evergreen shrubs or trees to 10 m tall. Foliage includes decurrent and scale types. Female cones (berries) are globose, 5-9(-10) mm diameter, blue-black, glaucous, with a soft, fleshy pulp, usually on curved peduncles. Seeds (2-)3-7(-9) per cone, angular, grooved. Pollen shed in the fall. Other characters variable, as described below (Adams 2004).
Adams 2004 provides the following key to the forms: |
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1a. |
Mature twigs 5-10 mm. long angle of branching of ultimate twig 50-60 degrees, foliage very dense and tightly compacted, prostrate shrubs (less than 1 m.), alpine habitat. |
f. compacta |
|
1b. |
Mature ultimate twigs 10-40 mm. long, angle of branching of ultimate twig 40-60 degrees, foliage loose, not tightly compacted, low shrub to tree (to 10 m.). |
2 |
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2a. |
Mature ultimate twigs 10-15(-20) mm. long; angle of branching of ultimate twig 40-50 degrees; foliage not tightly compacted; spreading, tortuous-stemmed shrub to tree to 10 m. |
f. monticola |
|
2b. |
Mature ultimate twigs 20-40 mm. long, angle of branching of ultimate twig 55-60 degrees, foliage not tightly compacted, shrubs to 1.5 m. |
f. orizabensis |
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Forma monticola is a tree or spreading shrub with tortuous branches, if a tree, then to 10 m with crown flattened to broadly conic. The bark is 5-10 mm thick, gray to gray-brown, exfoliating in fibrous, longitudinal strips. The terminal whip branches are spreading and tortuous to ascending, the tips occasionally curved, with red-brown to gray-brown bark. Scale leaves are usually opposite, gray-green to green, often thick, 1.0-2.0 mm long, rounded or obtuse with appressed tips, appearing as a string of beads on the ultimate twig. Their margins are finely denticulate, and there is sometimes an obvious resin gland on the surface of the leaf (Adams 2004).
Forma compacta is a prostrate shrub less than 1 m tall with twisted, procumbent branches. The bark is cinnamon brown, exfoliating in thin strips (Adams 2004).
Forma orizabensis is a shrub up to 1.5 m tall with twisted, spreading branches. Trunk bark is light brown, exfoliating in thin strips or plates.
Mexico. The formae have disjunct distributions, the type in subalpine to alpine settings, the others confined to the alpine zone, as follows:
Forma monticola: Widespread in rocky subalpine (above treeline on Nevado de Colima, Jalisco) oak-juniper, Pinus or Abies forests, as an understory shrub or small tree, at 2,400 to 4,300 m elevation. It is widespread and not of commercial significance, and thus is not threatened (Adams 2004).
Forma compacta: Native in Coahuila (Sierra Mojada), Distrito Federal (Cerro Pelado and Ajusco), Jalisco (Nevado de Colima), México (Popocatepetl, Iztaccihuatl, Tlaloc and Nevado de Toluca), Nuevo Leon (Cerro Potosí), Tlaxcala (Malinche), and Veracruz (Cofre de Perote). It is found at 3000-4300(-4500) m elevation at the alpine timberline (with Pinus hartwegii) above in Calamagrostis and Festuca mountain grasslands, often on rocky sites. The form has no commercial significance, and thus is not threatened (Adams 2004).
Forma orizabensis: Native in Veracruz (Pico de Orizaba, Sierra Nevada, and Cofre de Perote), Tamaulipas (Peña Nevada), where it grows at and above the alpine timberline on rocky sites at 3700-4500 m elevation; and also in San Luis Potosi (Mineral Catoree), where it occurs at 2850 m elevation in oak forest. Although it has a very limited distribution, it occurs in relatively undisturbed alpine sites and is not threatened (Adams 2004).
Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (Bannister and Neuner 2001); the variety not specified.
No data as of 2023.03.03.
Adams, Robert P. 2004. Junipers of the World: The Genus Juniperus. Trafford Publishing.
Brief versions of the descriptions are available online at www.juniperus.org.
Adams, R.P. and T.A. Zanoni. 1993. Juniperus monticola (Cupressaceae) revisited. Taxon 42: 85-86.
Farjon (2005) provides a detailed account, with illustrations.
Last Modified 2023-03-03
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