Colorado Pinyon

Appearance

The piñon pine is a small to medium size tree, reaching 10–20 feet tall and with a trunk diameter of up to 80 centimetres, rarely more. The bark is irregularly furrowed and scaly. The leaves are in pairs, moderately stout, 3–5.5 cm long, and green, with stomata on both inner and outer surfaces but distinctly more on the inner surface forming a whitish band.

The cones are globose, 3–5 cm long and broad when closed, green at first, ripening yellow-buff when 18–20 months old, with only a small number of thick scales, with typically 5–10 fertile scales. The cones open to 4–6 cm broad when mature, holding the seeds on the scales after opening. The seeds are 10–14 mm long, with a thin shell, a white endosperm, and a vestigial 1–2 mm wing.

Distribution

The range is in Colorado, southern Wyoming, eastern and central Utah, northern Arizona, New Mexico, western Oklahoma, southeastern California, and the Guadalupe Mountains in far western Texas. It occurs at moderate altitudes of 1,600–2,400 metres, rarely as low as 1,400 m and as high as 3,000 m.

It is widespread and often abundant in this region, forming extensive open woodlands, usually mixed with junipers in the pinyon-juniper woodland plant community. The Colorado pinyon grows as the dominant species on 4.8 million acres in Colorado, making up 22% of the state's forests. The Colorado pinyon has cultural meaning to agriculture, as strong piñon wood "plow heads" were used to break soil for crop planting at the state's earliest known agricultural settlements.

There is one known example of a Colorado pinyon growing amongst Engelmann spruce and limber pine at nearly 3,170 metres on Kendrick Peak in the Kaibab National Forest of northern Arizona.