Arizona Pine

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{{Taxobox | color = lightgreen | name = Arizona Pine | regnum = Plantae | divisio = Pinophyta | classis = Pinopsida | ordo = Pinales | familia = Pinaceae | genus = Pinus | subgenus = Pinus | species = P. arizonica | binomial = Pinus arizonica | binomial_authority = Engelm. }}

The Arizona Pine {Pinus arizonica) is a medium-sized pine in northern Mexico, southeast Arizona, southwest New Mexico, and western Texas in the United States. It is a tree growing to 25-35 m tall, with a trunk diameter of up 1.2 m. The needles are in bundles of 3, 4, or 5, with 5-needle fascicles being the most prevalent. This variablity may be a sign of hybridization with the closely related Ponderosa Pine (Pinus ponderosa). The cones are single, paired, or in whorls of three, and 5-11 cm long.

It has been thought to be a variant of Ponderosa Pine by some botanists in the past, but is now recognized as a distinct species by most authorities.

Two varieties are described, possibly better treated as distinct species; see Ponderosa Pine for a table of characters:

• Pinus arizonica var. arizonica, in the Sierra Madre Occidental from Arizona south to Durango
• Pinus arizonica var stormiae, in the Sierra Madre Oriental from the Big Bend National Park in Texas south to San Luis Potosí.

Another related pine, Cooper's Pine (Pinus cooperi) is also treated as a variety of Arizona Pine by some authors, as Pinus arizonica var. cooperi, but other authors regard this as a distinct species, more closely related to Hartweg's Pine (Pinus hartwegii).

This pine is a source of construction timber, and is heavily harvested for firewood. Extensive cutting has reduced the formerly widespread Arizona Pine forests, particularly in Mexico.