14a. Pinus leiophylla var. chihuahuana (Engelmann) G. R. Shaw, Pines Mexico. 14, plate 7, figs. 10, 11. 1909.
Chihuahua pine, pino real, pino prieto
Pinus chihuahuana Engelmann in Wislizenus, Mem. Tour N. Mexico, 103. 1848
Trees to 25m; trunk to 0.9m diam., slender; crown conic, becoming rounded. Bark brown to red-brown, narrowly furrowed, cross-checked into long, irregularly and narrowly rectangular, flat, scaly ridges. Branches ascending; twigs slender, orange-brown or glaucous and violet, aging red-brown, ±smooth or cracking. Buds ovoid, light red-brown, ca. 0.6--0.7(--1)cm, slightly resinous. Leaves (2--)3(--4) per fascicle, spreading-ascending, persisting 2 years, 6--15cm ´ 0.8--1mm, straight to slightly twisted, dull gray-green, all surfaces with fine stomatal lines, margins finely serrulate, apex acute to acuminate; sheath to 1.5cm, shed early and completely. Pollen cones broadly ellipsoid, ca. 10--15mm, brown or yellow. Seed cones maturing in 3 years, shedding seeds soon thereafter but long-persistent, paired or solitary, symmetric, lateral, narrowly ovoid before opening, broadly ovoid to nearly globose when open, 3.5--5(--9)cm, chestnut brown or greenish brown, aging gray to gray-brown, stalks to 1.5cm; apophyses slightly thickened and raised, not keeled; umbo central, slightly raised or depressed, with short, often deciduous prickle or unarmed. Seeds obovoid; body ca. 2mm, gray, mottled darker; wing ca. 10mm, dark-lined. 2 n =24.
Dry slopes and plateaus; 1500--2500m; Ariz., N.Mex.; Mexico.
Pinus leiophylla var. chihuahuana is one of the few pines that produce sprouts from stumps. It differs from the type variety in its dark, less roughened bark, its shorter range of leaf length, and its slightly broader leaves that occur more consistently in threes. (The narrower, often longer leaves of the type variety are in fours and fives.)
The type variety, Pinus leiophylla var. leiophylla , is exclusively Mexican.