Subsp. cembroides var. bicolor: Border piñon (Lanner 1981).
The systematics of this pine are more hotly debated than those of probably any other species in the genus. It is a widespread and morphologically diverse species, which has led to the description of numerous varieties and subspecies, most of which were later raised to the rank of species by their respective authors. Three are held as species in this treatment:
The remaining infraspecific taxa include:
Additionally, some authors (e.g., Kral (1993)) have chosen to include P. remota (Little) D.K.Bailey & Hawksworth in synonymy with P. cembroides, but Farjon and Styles (1997) retain it as a distinct species. The following description does not discriminate the two species. Kral's (1993) argument that var. remota is questionably valid as a variety, let alone a species, follows:
"Pinus cembroides is the common Piñon of Mexican commerce. Populations of the Edwards Plateau, Texas, are disjunct about 150 km 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 Piñon 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."
"Shrubs or trees to 15 m; trunk to 0.3 m 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, 0.5-1.2 cm, slightly resinous. Leaves (2-)3(-4) per fascicle, spreading to upcurved, persisting 3-4 years, 2-6 cm x 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 10 mm, 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, 1-3.5 cm, 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. 2n=24." (Kral 1993).
Piñon-juniper woodland at 700-2400 m. USA: SE Arizona, SW New Mexico, W Texas (Lanner 1981, Kral 1993). See also Thompson et al. (1999). In Mexico, occurs in mountainous parts of most states N of latitude 20° (Perry 1991). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001).
The map below does not separate P. cembroides from P. discolor. I have not yet found a map that does.
Diameter 90 cm, height 20 m, crown spread 13 m, located in Big Bend National Park, TX (American Forests 1996). Larger trees probably occur in Mexico.
American Forests 1996. The 1996-1997 National Register of Big Trees. Washington, DC: American Forests. This is a dated citation; the big tree register is now available online.
Last Modified 2017-12-29