– Distribution and Habitat:
– Range in the U.S. includes Colorado, southern Wyoming, eastern and central Utah, northern Arizona, New Mexico, western Oklahoma, southeastern California, and the Guadalupe Mountains in far western Texas, as well as northern Mexico.
– Occurs at elevations of 1,600–2,400 meters, rarely as low as 1,400m and as high as 3,000m.
– Dominant species on 4.8 million acres in Colorado, making up 22% of the state’s forests.
– Found in open woodlands, usually mixed with junipers in the pinyon-juniper woodland plant community.
– Example of Colorado pinyon growing amongst Engelmann spruce and limber pine at nearly 3,170 meters in Arizona.
– Description:
– Small to medium-sized tree, reaching 10–20 feet tall with a trunk diameter of up to 80 centimeters.
– Growth rate is extremely slow, growing only six feet in 100 years under good conditions.
– Bark is irregularly furrowed and scaly.
– Leaves are in pairs, moderately stout, 3–5.5cm long, green, with stomata on both inner and outer surfaces.
– Cones are globose, 3–5cm long and broad when closed, ripening yellow-buff when 18–20 months old.
– Ecology:
– Seeds are dispersed by the pinyon jay, which uses them as a food resource.
– Pinyon jay stores many seeds for later use, allowing some to grow into new trees.
– Seeds are also eaten by wild turkey, Montezuma quail, and various mammals.
– History:
– Colorado pinyon was described by George Engelmann in 1848 near Santa Fe, New Mexico.
– Most closely related to the single-leaf pinyon, occasionally hybridizing in western Arizona and Utah.
– Closely related to the Texas pinyon but does not hybridize due to a 100-kilometer gap.
– Population of trees in southeast California previously thought to be Colorado pinyons were identified as a two-needled variant of single-leaf pinyon.
– Two-needled pinyons in northern Baja California are hybrids between single-leaf pinyon and Parry pinyon.
– Uses:
– Edible seeds, pine nuts, are extensively collected throughout its range.
– Seed harvest rights are owned by Native American tribes in many areas.
– Seeds can be stored for a year when unshelled.
– Colorado pinyon is used as an ornamental tree and sometimes as a Christmas tree.
– State tree of New Mexico.