Arizona pine

Pinus arizonica Engelmann in Rothrock, Wheeler, U.S. Geogr. Surv. West 100th Merid. Rep. 6: 260. 1878

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 .