Discover Life - Pinaceae: Pinus cembroides Zucc. - Mexican pine nut, Mexican Pinyon

Tree 6m tall at WP52 [C.J. Earle, 2007.02.10].

Same area, Tree 7m tall [C.J. Earle, 2007.02.10-017].

Tree 5m tall at WP250 [C.J. Earle, 2007.02.18].

Foliage [C.J. Earle, 2007.02.18-014].

Seedling 15cm tall [C.J. Earle, 2007.02.18-026].

Bark, biggest trunk is 25 cm diameter [C.J. Earle, 2007.02.10].

Pure forest north of La Escondida [C.J. Earle, 2007.02.19-10].

Distribution map ( Critchfield and Little 1966 ). Note that this map describes the species as including P. discolor , P. orizabensis and P. johannis (see the Taxonomic notes).

Pinus cembroides

Zuccarini 1832

Common names

Mexican piñon, stoneseed piñon, threeleaf piñon, pinyon pine ( Elmore and Janish 1976 ); pino piñonero ( Kral 1993 ).

Subsp. cembroides var. bicolor : Border piñon ( Lanner 1981 ).

Taxonomic notes

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:

P. discolor Bailey & Hawksworth,
P. orizabensis (D.K. Bailey) Bailey & Hawksworth and
P. johannis Robert.

The remaining infraspecific taxa include:

Subsp. cembroides var. cembroides (syn: P. llaveana Schiede ex Schlectendahl 1838; P. osteosperma Engelmann 1848).
Subsp. lagunae (Robert-Passini) Bailey 1983 .

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."

Description

"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. 2 n =24." ( Kral 1993 ).

Range

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°, with subsp. orizabensis found a bit farther south ( Perry 1991 ).

Big tree

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.

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© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Leaf	© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Leaf

© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Twig	© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Bark

© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Bark	© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Whole tree

© Copyright Steve Baskauf, 2002-2005 Pinus cembroides, Bark

Pinus cembroides Zucc.

Common names

Taxonomic notes

Description

Range

Big tree

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

See also