Editing Pinus monophylla (section)

==Description==
''Pinus monophylla'' is a small to medium size [[tree]], reaching {{cvt|10|-|20|m|ft}} tall and with a trunk diameter of up to {{cvt|80|cm|in|frac=4}} rarely more. The bark is irregularly furrowed and scaly. The [[leaves]] ('needles') are, uniquely for a pine, usually single (not two or more in a fascicle, though trees with needles in pairs are found occasionally), stout, {{cvt|4|-|6|cm|in|frac=4}} long, and grey-green to strongly glaucous blue-green, with [[stomata]] over the whole needle surface (and on both inner and outer surfaces of paired needles). The [[conifer cone|cones]] are acute-globose, the largest of the true pinyons, {{cvt|4.5|-|8|cm|in|frac=8}} long and broad when closed, green at first, ripening yellow-buff when 18–20 months old, with only a small number of very thick scales, typically 8–20 fertile scales. The cones thus grow over a two-year (26-month) cycle, so that newer green and older, seed-bearing or open brown cones are on the tree at the same time.

[[File:Pinyon with pine nuts in cone.jpg|right|thumb|upright=0.86|Open cone with empty pine nuts]]
The [[seed cone]]s open to {{cvt|6|-|9|cm|in|frac=4}} broad when mature, holding the [[seed]]s on the scales after opening. The seeds are {{cvt|11|-|16|mm|in|frac=16}} long, with a thin shell, a white [[endosperm]], and a vestigial {{cvt|1|-|2|mm|in|frac=32}} wing. Empty pine nuts with undeveloped seeds (self-pollinated) are a light tan color, while the "good" ones are dark brown.<ref name="Lanner1981">Ronald M. Lanner 1981</ref> The pine nuts are dispersed by the [[pinyon jay]], which plucks the seeds out of the open cones, choosing only the dark ones and leaving the light ones (as in image at right).  The jay, which uses the seeds as a food resource, stores many of the seeds for later use by burying them. Some of these stored seeds are not used and are able to grow into new trees.  Indeed, Pinyon seeds will rarely germinate in the wild unless they are cached by jays or other animals.