WikiWorks at 14:29, 27 March 2007

2007-03-27T14:29:21Z

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{{Taxobox
| color = lightgreen
| name = Mexican Pinyon
| status = LR/lc
| image = Pinus cembroides.jpg
| image_width = 240px
| image_caption = Mexican Pinyon in [[Big Bend National Park]], [[Texas]]
| regnum = [[Plant]]ae
| divisio = [[Pinophyta]]
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Pinales]]
| familia = [[Pinaceae]]
| genus = ''[[Pine|Pinus]]''
| subgenus = ''[[Pinus classification|Ducampopinus]]''
| species = '''''P. cembroides'''''
| binomial = ''Pinus cembroides''
| binomial_authority = [[Joseph Gerhard Zuccarini|Zucc.]]
}}

The '''Mexican Pinyon''' (''[[Pinus]] cembroides'') is a [[pine]] in the [[pinyon pine]] group, native to [[North America]]. The range extends from westernmost [[Texas]], [[United States]] (where it is restricted to the Chisos and [[Davis Mountains]]) south through much of [[Mexico]], occurring widely along the [[Sierra Madre Oriental]] and [[Sierra Madre Occidental]] ranges, and more rarely in the eastern [[Eje Volcánico Transversal]] range. There is also a disjunct population in the [[Sierra de la Laguna]] of southern [[Baja California Sur]]. It occurs at moderate altitudes, mostly from 1600-2400 m.

It is a small to medium-size [[tree]], reaching 8-20 m tall and with a trunk diameter of up to 50 cm. The bark is dark brown, thick and deeply fissured at the base of the trunk. The [[leaf|leaves]] ('needles') are in mixed pairs and threes, slender, 3-6 cm long, and dull yellowish green, with [[stomata]] on both inner and outer surfaces. The [[conifer cone|cones]] are globose, 3-4 cm long and broad when closed, green at first, ripening yellow-brown when 18-20 months old, with only a small number of thick scales, with typically 5-12 fertile scales. The cones open to 4-5 cm broad when mature, holding the [[seed]]s on the scales after opening. The seeds are 10-12 mm long, with a thick shell, a pink [[endosperm]], and a vestigial 2 mm wing; they are dispersed by the [[Mexican Jay]], which plucks the seeds out of the open cones. The jay, which uses the seeds as a major food resource, stores many of the seeds for later use, and some of these stored seeds are not used and are able to grow into new trees.

Mexican Pinyon was the first [[pinyon pine]] described, named by [[Joseph Gerhard Zuccarini|Zuccarini]] in [[1832]]. Many of the other pinyon pines have been treated as [[variety (biology)|varieties]] or [[subspecies]] of it at one time or another in the past, but research in the last 10-50 years has shown that most are distinct [[species]]. Some botanists still include [[Johann's Pinyon]] and [[Orizaba Pinyon]] in Mexican Pinyon; the former accounts for records of "Mexican Pinyon" in southern [[Arizona]] and [[New Mexico]].

Mexican Pinyon is a relatively non-variable species, with constant morphology over the entire range except for the [[Disjunct distribution|disjunct]] population in the [[Sierra de la Laguna pine-oak forests]] of Baja California Sur; this is generally treated as a subspecies, ''Pinus cembroides'' subsp. ''lagunae'', although some botanists treat it as a separate species, ''P. lagunae.'' This subspecies differs from the type in having slightly longer leaves (4-7 cm) and longer, narrower cones, up to 5.5 cm long.

The seeds are widely collected in Mexico, being the main [[pine nut]] in the region.

==References==
* {{IUCN2006|assessors=Conifer Specialist Group|year=1998|id=42350|title=Pinus cembroides|downloaded=12 May 2006}}

==External links==
*[http://www.pinetum.org/PhotoMPF.htm Photos of tree and foliage]
*[http://www.pinetum.org/cones/PNDucampopinus.htm Photo of cones (scroll half-way down)]

[[Category:Pinaceae|Pinyon, Mexican]]
[[Category:Trees of Mexico|Pinyon, Mexican]]
[[Category:Trees of Northern Mexico|Pinyon, Mexican]]
[[Category:Trees of Baja California Sur|Pinyon, Mexican]]

[[Category:Trees of Arizona|Pinyon, Mexican]]
[[Category:Trees of New Mexico|Pinyon, Mexican]]
[[Category:Trees of Western Texas|Pinyon, Mexican]]

Mexican Pinyon - Revision history

WikiWorks at 14:29, 27 March 2007