Vascular Plants of the Gila Wilderness

Presented in Association with the
Western New Mexico University Department of Natural Sciences

Juniperus monosperma (Engelmann) Sargent
(One Seeded Juniper)

Family: Cupressaceae

Status: Native

Synonyms:
Juniperus gymnocarpa (Lemmon) Cory
Juniperus mexicana Sprengel var., monosperma (Engelmann) Cory
Juniperus occidentalis Hooker var. monosperma Engelmann

Juniperus monosperma is less common than Juniperus deppeana but shares the same approximate geographic distribution in the Gila National Forest. In some areas, Juniperus monosperma is locally more common. It is easily recognized by the stringy, linear bark on the trunk and larger branches. Juniperus monosperma is dioecious, meaning that there are separate male and female trees. The leaves do not have an obvious white exudate. The berry-like glaucous pinkish-purple seed cones have one or sometimes two seeds within them. They are smaller than the seed cones of Juniperus deppeana. The seeds are lightly ridged.
The individual leaves of J. monosperma, like those of J. deppeana, are appressed to the stems. However, fewer of the leaves of J. monosperma have visible exudate on the abaxial surface. The leaves of J. monosperma are denticulate margined, while leaves of J. scopulorum are entire. On cross section, there are also differences, but they are difficult to see. There appear to be 6-8 smaller resin channels in a row across the leaves of J. monosperma, rather than the 2 larger resin channels apparent in leaf cross sections of J. deppeana.
Please click on an image for a larger file.



Juniperus monosperma, photo Russ Kleinman & Karen Blisard, Burro Mtns, Wild Horse Canyon, May 16, 2007



Juniperus monosperma, 1x macro of twig with pollen cone and absence of white exudate on leaves, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 8, 2008



Juniperus monosperma, 3x macro of twig with pollen cone and absence of white exudate on leaves, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 8, 2008



Juniperus monosperma, twig with seed cones, photo Russ Kleinman & Richard Felger, Burro Mtns., WD Ranch Road, Dec. 29, 2008



Juniperus monosperma, 1x macro of seed cone, photo Russ Kleinman, Pinos Altos Range, Fort Bayard, Dec. 19, 2008



Juniperus monosperma, 2x macro of slightly ridged and pointed single seed in seed cone, photo Russ Kleinman, Pinos Altos Range, Fort Bayard, Dec. 19, 2008



Juniperus monosperma, closeup of seed cone, photo Russ Kleinman & Richard Felger, Burro Mtns., WD Ranch Road, Dec. 29, 2008



Juniperus monosperma, growth form (note Phoradendron capitellatum), photo Russ Kleinman & Richard Felger, Burro Mtns., WD Ranch Road, Dec. 29, 2008



Juniperus monosperma, branch with cones, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, August 22, 2012



Juniperus monosperma, photomicrograph of leaf abaxial surface, photo Russ Kleinman & Karen Blisard, Pinos Altos Range, Pinos Altos, February 14, 2018



Juniperus monosperma, photomicrograph of leaf cross section, photo Russ Kleinman & Karen Blisard, Pinos Altos Range, Pinos Altos, February 14, 2018



Juniperus monosperma, photomicrograph of leaf margins of J. monosperma and J. scopulorum, photo Russ Kleinman, Bill Norris and the 2022 WNMU Dendrology Class, September 8, 2022, Silver City (J. scopulorum) and Pinos Altos (J. monosperma)


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