See Juniperus scopulorum and Juniperus deppeana  and  Juniperus osteosperma.

Semi-desert. Shrublands, woodlands. Spring.
Painted Desert area of Petrified Forest National Park, Arizona. March 24, 2007.

Juniperus monosperma is typically a small, symmetrical tree about three meters high with a number of thin, curved branches emanating from the base.  The taller Juniperus osteosperma often has a more open appearance with few stout branches from a massive central trunk.  Juniperus monosperma grows in central and southeastern Colorado (and in a few isolated populations in two northwestern counties), in almost all counties of New Mexico and Arizona, and in those counties of Utah that border on Arizona.  There are no official records of it in Colorado in the Four Corners area.

George Engelmann named this tree Juniperus occidentalis variety monosperma in 1878 from specimens collected (by Engelmann?) probably near Pike's Peak.  Charles Sargent named it Juniperus monosperma in 1896 and Per Axel Rydberg named it Sabina monosperma in 1905.

Semi-desert. Shrublands, woodlands. Spring.
Petrified Forest National Park, Arizona. March 24, 2007.

Juniperus monosperma is dioecious (male and female flowers on separate trees) whereas Juniperus osteosperma is usually monoecious.  In the photograph at left, male flowers are about to open and flood the air with yellow pollen.

Semi-desert. Shrublands, woodlands. Spring.
De-Na-Zin/Bisti Wilderness, October 8, 2007.

Female trees have blue, cone-like structures which mature in one season.  The cones house the seeds and are full of liquid resin --  in contrast to the dry and mealy cones of Juniperus osteosperma. 

Range map © John Kartesz,
Floristic Synthesis of North America

State Color KeySpecies present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Juniperus monosperma