Pinus arizonica

Arizona pine
Pinus arizonica sapling
Conservation status
Least Concern  (IUCN 2.3)
Scientific classification
Kingdom:	Plantae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Pinaceae
Genus:	Pinus
Subgenus:	Pinus
Species:	P. arizonica
Binomial name
Pinus arizonica Engelm.
Natural range of Pinus arizonica green: Pinus arizonica var. arizonica red: Pinus arizonica var. stormiae blue: P. ponderosa ssp. brachyptera

Pinus arizonica, commonly known as the Arizona pine, 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 (3 ft 11 in). The needles are in bundles of 3, 4, or 5, with 5-needle fascicles being the most prevalent. This variability 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.

Taxonomy

The Arizona pine had been thought to be a variant of Ponderosa pine by some botanists, but is now recognized as a distinct species by most authorities.

P. arizonica forest, Mt. Lemmon, AZ

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).

Uses

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.

References

• Conifer Specialist Group (1998). Pinus arizonica. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 12 May 2006.