Shrubs or trees to 15m; trunk to 0.3m diam., strongly tapering, much branched; crown rounded. Bark red-brown to dark brown, shallowly and irregularly furrowed, ridges broad, scaly. Branches spreading-ascending; twigs red-brown, sometimes finely papillate, aging gray to gray-brown. Buds ovoid to short cylindric, pale red-brown, 0.5--1.2cm, slightly resinous. Leaves (2--)3(--4) per fascicle, spreading to upcurved, persisting 3--4 years, 2--6cm ´ 0.6--0.9(--1)mm, connivent, 2--3-sided, blue- to gray-green, abaxial surface not conspicuously whitened with stomatal bands or if stomatal bands present, these less conspicuous than on adaxial surfaces, often with 2 subepidermal resin bands evident, adaxial surfaces conspicuously whitened with stomatal lines, margins entire to finely serrulate, apex narrowly conic or subulate; sheath 0.5--0.7cm, scales soon recurved, forming rosette, shed early. Pollen cones ellipsoid, to 10mm, yellow. Seed cones maturing in 2 years, shedding seeds and falling soon thereafter, spreading, symmetric, ovoid before opening, broadly depressed-ovoid to nearly globose when open, 1--3.5cm, pale yellow- to pale red-brown, resinous, nearly sessile or short-stalked; apophyses thickened, slightly domed, angulate, transversely keeled; umbo subcentral, slightly raised to depressed, truncate or umbilicate. Seeds ovoid to obovoid; body (7--)12--15(--20)mm, brown, wingless. 2 n =24.
Pinus cembroides is the common pinyon of Mexican commerce. Populations of the Edwards Plateau, Texas, are disjunct about 150km east and north of the main area of distribution of the species, and they have been described as a distinct variety, P . cembroides var. remota Little, on the basis of thin seed shell and a higher frequency of 2-leaved fascicles in contrast to the thicker seed shell and prevalently 3-leaved fascicles in Mexican pinyon populations to the west and south. The strong overlap in nearly all character states between the populations of the Edwards Plateau and other populations makes var. remota difficult to maintain.
Malusa 1992, FNA 1993, Perry 1991, Kearney and Peebles 1969
Common Name: Border Pinyon Duration: Perennial Nativity: Native Lifeform: Tree General: A small tree 5-10 m tall, with a trunk 10-50 cm in diameter, the crown open and irregularly rounded; bark dark gray, furrowed with smaller transverse fissures, in deeper furrows an orange colored hue is visible. Needles: In fascicles of 3, occasional but rarely 2 or 4, 2-6 cm long, 1.3-1.6 mm wide, straight, slender, flexible, margins entire; the adaxial surface very glaucous, abaxial surface dark green; sheaths thin, pale brown, recurved into a rosette, deciduous. Cones: Symmetrical, very small, 2-3 cm long, 3-4 cm wide when open, pale orange to reddish brown, opening when mature and soon deciduous, on short peduncle 3-6 mm long that falls with cone; scales without a prickle. Seeds: Small, wingless, 10-12 mm long, 7-10 mm wide, brown with thick, 0.7-1.2 mm thick, hard seed coat. Ecology: Found on arid slopes and flats from 5,000-8,000 ft (1524-2438 m). Distribution: s AZ, s NM, s TX; south to c MEX. Notes: This variety is suggested to be the sole variety of P. cembroides in southeastern Arizona parklands and the principal pinyon of the Mexican borderlands. Distinguished by the short stature of the tree compared to other pines; short needles in fascicles of three; and the small cones. Ethnobotany: The nuts were widely collected and eaten, while the pitch can be used for wounds or cuts. Etymology: Pinus is the ancient Latin name for pines, while discolor comes from the Greek dis- which can mean two or without, as in two colors or without color. Synonyms: Pinus discolor, Pinus culminicola var. bicolor, Pinus johannis Editor: SBuckley 2010, FSCoburn 2015