Editing Pinus edulis (section)

== Description ==
The piñon pine (''Pinus edulis'') is a small to medium size [[tree]], reaching {{convert|10|-|20|ft|order=flip}} tall and with a trunk diameter of up to {{convert|80|cm|in}}, rarely more. Its growth is "at an almost inconceivably slow rate" growing only 1.8 meters (6 ft) in one hundred years under good conditions.<ref>{{cite journal |last=Rehorn |first=John T. |date=Winter–Spring 1997 |title=The Gift |journal=American Forests |volume=103 |issue=1 |page=28 caption}}</ref>  for an average growth of 18 millimeters (0.72 in) per year. The bark is irregularly furrowed and scaly. The [[leaves]] ('needles') are in pairs, moderately stout, {{convert|3|-|5.5|cm|in|frac=8|abbr=on}} long, and green, with [[stomata]] on both inner and outer surfaces but distinctly more on the inner surface forming a whitish band.

The [[conifer cone|cones]] are globose, {{convert|3|-|5|cm|in|frac=4|abbr=on}} 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 {{convert|4|-|6|cm|in|frac=4|abbr=on}} broad when mature, holding the [[seed]]s on the scales after opening. The seeds are {{convert|10|-|14|mm|in|frac=16|abbr=on}} long, with a thin shell, a white [[endosperm]], and a vestigial {{convert|1|-|2|mm|in|frac=32|abbr=on}} wing.

The species intermixes with Pinus monophylla sbsp. fallax (see description under ''[[Pinus monophylla]]'') for several hundred kilometers along the Mogollon Rim of central Arizona and the Grand Canyon resulting in trees with both single- and two-needled fascicles on each branch.  The frequency of two-needled fascicles increases following wet years and decreases following dry years.<ref>{{cite journal |last1=Cole |first1=Ken |last2=Fisher |first2=Jessica |last3=Arundel |first3=Samantha |last4=Canella |first4=John |last5=Swift |first5=Sandra |date=2008 |title=Geographical and climatic limits of needle types of one- and two-needled pinyon pines |journal=Journal of Biogeography |volume=35 |issue=2 |pages=357–369 |doi=10.1111/j.1365-2699.2007.01786.x |pmc=3001037 |pmid=21188300|bibcode=2008JBiog..35..257C }}</ref>  The internal anatomy of both these needle types are identical except for the number of needles in each fascicle suggesting that Little's 1968 designation <ref>{{cite journal |last1=Little |first1=Elbert |date=1968 |title=Two new pinyon varieties from Arizona |journal=Phytologia |volume=17 |pages=329–342}}</ref> of this tree as a variety of Pinus edulis is more likely than its subsequent designation as a subspecies of Pinus monophylla based entirely upon its single needle fascicle.

It is an aromatic species. Essential oil can be extracted from the trunk, limbs, needles, and seed cones. Prominent aromatic compounds from each portion of the tree include α-pinene, sabinene, β-pinene, δ-3-carene, β-phellandrene, ethyl octanoate, longifolene, and germacrene D.<ref>{{Cite journal |last=Poulson A, Wilson TM, Packer C, Carlson RE, Buch RM |title=Essential oils of trunk, limbs, needles, and seed cones of Pinus edulis (Pinaceae) from Utah |journal=Phytologia |volume=102 |issue=3 |pages=200–207}}</ref>
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File:Pinus edulis Snowpeak.jpg|Cones of ''P.&nbsp;edulis''
File:Pinon1512.jpg|Foliage
File:2012.09.14.122141 Tree Yavapai Point Grand Canyon Arizona.jpg|Trunk
</gallery>