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A mature tree in the Santa Rita Mountains, Arizona [C.J. Earle, 2012.12.28].


A complete foliar unit bearing immature cones; the Santa Rita Mountains, Arizona [C.J. Earle, 2012.12.28].


Foliage and an immature cone on a tree near Cuahtemoc, Coahuila [Jeff Bisbee, 2014.09].


A large tree in the Santa Rita Mountains, Arizona [C.J. Earle, 2012.12.28].


A "grass stage" seedling along with real bunch grasses; the Santa Rita Mountains, Arizona [C.J. Earle, 2014.04.20].


Abundant regeneration in the aftermath of a fire 9 years earlier; the Santa Rita Mountains, Arizona [C.J. Earle, 2014.04.20].


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Conservation status

Pinus engelmannii

Carrière 1854

Common names

Apache pine, Arizona longleaf pine (Elmore and Janish 1976).

Taxonomic notes

Syn: Pinus latifolia Sargent 1889 (Peattie 1950); P. macrophylla Engelmann in Wislizenus 1848, non Lindley 1839; P.apacheca Lemmon 1894 (Kral 1993); P. ponderosa var. macrophylla (Engelmann) Shaw 1909; P. mayriana Sudworth 1897; P. ponderosa var. mayriana (Sudworth) Sargent 1897; P. macrophylla var. blancoi Martínez 1944; P. engelmannii var. blancoi (Martínez) Martínez 1948 (Farjon and Styles 1997).


"Trees to 35 m; trunk to 0.6 m diam., straight; crown irregularly rounded, rather thin. Bark dark brown, at maturity deeply furrowed, ridges becoming yellowish, of narrow, elongate, scaly plates. Branches straight to ascending; twigs stout (1-2 cm thick), pale gray-brown, aging darker brown, rough. Buds ovoid-conic, to 2 cm, resinous; scale margins pale fringed. Leaves 3(-5) per fascicle, spreading-ascending, often drooping, forming a brush at twig tips, persisting 2 years, (20-)25-45cm x 2 mm, dull green, all surfaces with fine stomatal lines, margins coarsely serrulate, apex conic-subulate; sheath 3-4 cm, base persistent. Pollen cones cylindric, ca. 25 mm, yellow to yellow-brown. Seed cones maturing in 2 years and shedding seeds soon thereafter, not persistent, terminal, sometimes curved, often asymmetric, lance-ovoid before opening, ovoid when open, 11-14 cm, light dull brown, nearly sessile or short-stalked; apophyses rhombic, somewhat to quite elongate, strongly raised toward outer cone base, sometimes curved, strongly cross-keeled, narrowed to thick, curved, broadly triangular-based umbo, this often producing outcurved claw. Seeds obovoid; body ca. 8-9 mm, dark brown; wing to 20mm. 2n=24" (Kral 1993).

"In general appearance Pinus engelmannii much resembles P. palustris with its short-persistent, long leaves (but in this species drooping) and in its tendency to form a grass stage (see the "Remarks" section of P. devoniana for details on "grass stage" growth). It has a deep taproot as do P. palustris and P. ponderosa" (Kral 1993).

Distribution and Ecology

USA: SE Arizona and SW New Mexico; Mexico: Sonora, Chihuahua, NE Sinaloa, Durango, Zacatecas, Nuevo Leon (Farjon and Styles 1997). It grows at (1200-)1500-2700(-3000) m, in high and dry mountain ranges, valleys, and plateaus (Elmore and Janish 1976, Farjon and Styles 1997). Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001). See also Thompson et al. (1999).

Distribution data from USGS (1999).

Ecologically, this species is something of a western analog to P. palustris, a species of the southeast U.S. coastal plain. Both species have extraordinarily long needles, are dominant species in frequently pure stands, are finely adapted to low-intensity fire with fire frequencies of <5 years, and have "grass stage" seedlings that are highly tolerant of such fires. Even in less frequently burned habitats, it appears that this species is capable of being a very effective competitor in the aftermath of severe fire (photo at left), an observation quite different from that reported by Barton (2002), who found seedlings to be rare after severe fire.

Big tree

There are two co-champions growing in Arizona: one is 32.9 m tall and 103 cm dbh, the other is 34.1 m tall and 98 cm dbh (Robert Van Pelt e-mail 2004.02.04).





It can readily be seen in the northern Chiricahua and Santa Rita Mountains (Arizona). In the former, it is common in Chiricahua National Monument. In the latter, it is easily found in Madera Canyon.


The epithet honor Georg Engelmann (1809-1884), one of the premier botanists of mid-19th Century America. Engelmann named about 20 western North American conifer taxa.

This species is a principal host for the dwarf mistletoes Arceuthobium globosum subsp. globosum, A. rubrum, A. vaginatum subsp. vaginatum, A. vaginatum subsp. cryptopodum, and A. verticilliflorum (Hawksworth and Wiens 1996).

This may be the premier pine in its region. It can attain quite large sizes and form a majestic emergent tree amidst lesser species that often include Pinus ponderosa, P. arizonica, P. leiophylla var. chihuahuana, P. strobiformis, and Pseudotsuga menziesii. It is a remarkably attractive species and in places appears, due to its fire adaptations, to form the keystone species for its forest ecosystem. I find it remarkable that almost no studies have examined this species, except to assess its genetics and calculate its timber potential.


Barton, Andrew M. 2002. Intense wildfire in southeastern Arizona: transformation of a Madrean oakā€“pine forest to oak woodland. Forest Ecology and Management 165(1):205-212.

Carrière, E. A. 1854. Thuia gigantea et autres conifères de la Californie et du Mexique septentrional. Rev. Hort. 4(3):223-229 (p. 227).

See also

Yeaton, R. I., R. W. Yeaton, and J. P. Waggoner III. 1983. Changes in morphological characteristics of Pinus engelmannii over an elevational gradient in Durango, Mexico. Madroño 30(3):168-175.

Last Modified 2014-12-12