Trees to 30m; trunk to 1.2m diam. Twigs mostly purple or red-brown, usually glaucous. Buds slightly resinous. Leaves mainly 4--5 per fascicle, 7--17cm ´ 1--1.2(--1.5)mm. Pollen cones mostly yellow. Seed cones often asymmetric, 5--8cm; apophyses at abaxial base often strongly raised, frequently mammillate; umbo low, broadly pryamidal, and merely acute or with very short apiculus. Seed body 3--4mm; wing to 15mm. 2 n =24.
Slopes, canyons and rims, and tablelands; 2100--2500m; Ariz., N.Mex.; Mexico.
The least common, least accessible ponderosa pine in the flora is Pinus ponderosa var. arizonica . It has leaves ranging widely in number per fascicle and in length, perhaps an expression of intergradation with P . ponderosa var. scopulorum , with which it is sympatric over broad areas.
Texas (Chisos Mountains) pines that are referred by some workers to P . ponderosa var. arizonica , belong to P . ponderosa var. scopulorum .
Perry 1991, FNA 1993, Kearney and Peebles 1969
Common Name: Arizona pine Duration: Perennial Nativity: Native Lifeform: Tree General: Trees with straight trunks 30-35 m tall, up to 1 m in diameter; branches are thick and strong, lower ones drooping, upper ascending, crown thick and rounded in mature trees; bark irregularly fissured with reddish, brown scaly plates. Needles: Borne in fascicles of 3-5 needles, stiff, erect, 12-22 cm long, growing in clusters at the end of branchlets. Stomata are present on the dorsal and ventral surfaces, margins finely serrate, with 6-10 resin canals, medial; fascicle sheaths brown up to 15 mm long. Cones: Ovoid to conical, symmetrical, erect to slightly reflexed, 6-9 cm long, borne singly, in twos or threes on short, stout peduncles, reddish brown; scales stiff about 12-14 mm wide, apical margin rounded and smooth, transversely keeled, ashy gray and bearing a sharp persistent, recurved prickle. Seeds: Dark brown, oval, about 6 mm long, articulate wing 20-25 mm long and 8-9 mm wide. Ecology: Found on deep, well-drained soils in valleys, on mesas, and in the mountains from 6,500-9,500 ft (1981-2896 m). Notes: Although this species' precise identity is in some question, with some suggestion that it is actually P. ponderosa var. arizonica, Perry 1991 suggests that it is much more clearly delineated. He suggests t that while the two are related, one need only look at the needles: 3-5 is the standard number for P. arizonica (usually 4) as opposed to only 2-3 in P. ponderosa; the cone scales have a small recurved prickle while P. ponderosa has a large, strong, and erect prickle; and finally, there are 6-10 resin canals in P. arizonica as opposed to only 2-6 in P. arizonica. Perry suggests using a hand lens you can clearly distinguish between the two. Recent phylogenetics place this as its own species without question, but one distributed in southeastern Arizona and northern Mexico. Ethnobotany: Unknown for this species, but all pines have a variety of uses. Etymology: Pinus is the ancient Latin name for pines, while arizonica means of or from Arizona. Synonyms: None Editor: SBuckley, 2010