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.
FNA 1993, Perry 1991, Kearney and Peebles 1969
Common Name: Chihuahuan pine Duration: Perennial Nativity: Native Lifeform: Tree General: Medium sized tree reaching 25 m tall with a trunk 40-90 cm in diameter, slender; the crown is conic, becoming rounded in age; bark brown to red-brown, narrowly furrowed, cross-checked into long, irregularly and narrowly rectangular flat, scaly ridges that separate longitudinal plates. Needles: In fascicles of 3 needles, rarely 4-5, spreading ascending, persisting 2 years, borne in clusters at the end of branchlets, 6-15 cm long by 0.8-1 mm thick, bearing 4-7 resin canals; dull gray green, all surfaces with fine stomatal lines, and finely serrulate margins; the fascicle sheaths are pale brown, to 1.5 cm long and are early deciduous. Cones: Long-ovoid, symmetrical, 4-7 cm long, persistent and reflexed on strong peduncles 7-12 mm long, bright yellowish green before maturing, then becoming dark brown; the cones are unique in that they require three years to mature, always persisting on the branches. Seeds: Very small, 3-4 mm, bearing a wing 7-10 mm long, articulate. Ecology: Found in shallow to sandy or even rocky soils, in the mountains, and on gentle slopes from 5,000-7,500 ft (1524-2286 m). Notes: This species is easily recognizable by the persistent cones, which makes it the only native pine cones that take three years to mature. This species is often associated with other species, never does it form uniform stands. In our region it is associated with pine and oak woodlands. Ethnobotany: Unknown for this species, but all pines have a variety of uses. Etymology: Pinus is the ancient Latin name for pines, while leiophylla comes from Greek leios, for smooth and phylla meaning leaf. The variety name refers to Chihuahua state in Mexico, where the type specimen of var. leiophylla can be found. Synonyms: None Editor: SBuckley, 2010