Juniperus monosperma

This juniper is one of the most common small trees in New Mexico. The wood is used for fenceposts and fuel. Juniperus monosperma is native to the U.S. and is in the Cupressaceae (Cypress Family).
Photo Credit: © James L. Reveal, USDA-NRCS PLANTS Database.
Juniperus monosperma
Common Name: oneseed juniper
Other Common Names: enebro de sombra
Plant Functional Group: Evergreen conifer
Class > Order > Family: Pinopsida > Pinales > Cupressaceae
What does the species look like?

Juniperus monosperma is an evergreen, coniferous, perennial shrub or small tree 12 to 36 feet tall with a heavily branched trunk. Its bark is gray to brown, thin, and scaly. The scale-like foliage is dark green and fragrant; mistletoe often grows in its canopy.The trees are dioecious with the male (pollen) and female (seed) cones on different plants. Seeds of oneseed juniper are dispersed through runoff, gravity, and birds and mammals.

Oneseed juniper has low water use and is tolerant of shade. It likes gravelly or sandy dry soils; dry, rocky slopes, arroyos; dry plains and hills. This species of juniper is tolerant to cold, wind, and drought. It occurs at elevations of 281 to 546 feet (515 1,000 to 2,300 m).

Birds and mammals consume the fleshy, berry-like seeds, and goats browse the foliage. This plant provides shelter for a variety of wildlife.
Where is the species found?
States & Provinces
AZ, CO, NM, OK, TX, UT
Special Considerations for Observing

Note that individuals of this species with only male cones will not produce fruit.
Which phenophases should I observe?
Do you see...?
Pollen cones Pollen cones
One or more fresh, male pollen cones (strobili) are visible on the plant. Cones have overlapping scales that are initially tightly closed, then spread apart to open the cone and release pollen. Include cones that are unopened or open, but do not include wilted or dried cones that have already released all of their pollen.
More...

How many fresh pollen cones are present?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Open pollen cones
One or more open, fresh, male pollen cones (strobili) are visible on the plant. Cones are considered "open" when the scales have spread apart to release pollen. Do not include wilted or dried cones that have already released all of their pollen.

What percentage of all fresh pollen cones (unopened plus open) on the plant are open?

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Pollen release
One or more male cones (strobili) on the plant release visible pollen grains when gently shaken or blown into your palm or onto a dark surface.
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How much pollen is released?

  • Little: Only a few grains are released.
  • Some: Many grains are released.
  • Lots: A layer of pollen covers your palm, or a cloud of pollen can be seen in the air when the wind blows

Seed cones Unripe seed cones
One or more unripe, female seed cones are visible on the plant. For Juniperus monosperma, an unripe seed cone is berry-like and green.
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How many seed cones are unripe?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Ripe seed cones
One or more ripe, female seed cones are visible on the plant. For Juniperus monosperma, a berry-like seed cone is considered ripe when it has turned dark blue, purple or brownish blue, often covered with a whitish film that rubs off.
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How many seed cones are ripe?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Recent cone or seed drop
One or more seed cones or seeds have dropped or been removed from the plant since your last visit. Do not include empty seed cones that had long ago dropped all of their seeds but remained on the plant.
More...

How many seed cones have dropped seeds or have completely dropped or been removed from the plant since your last visit?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
What do these phenophases look like?

There is currently no photoguide available for this species. If you'd like help us create one, use the guidance document and species template provided here. Then send it via email to education@usanpn.org when it is complete.

USDA PLANTS profile for oneseed juniper (USDA Symbol: JUMO )