Picea chihuahuana Martínez 1942

Common Names

Chihuahua spruce (1). Pinabete de Chihuahua (Mexican Spanish).

Taxonomic notes

Picea martinezii Patterson is sometimes considered synonymous with it (1), but proved clearly distinct on detailed analysis,"justifying the retention of P. martinezii as a separate species" (3).

Description

A tree to 25-35 m tall and 45-70 cm dbh, with pale grey furrowed and scaling bark. Crown narrow-conic, open with few long level branches among more numerous very short branches (photos in 4, 5). Shoots stout, pale buff. Leaves blue-green, matt with conspicuous stomatal lines, 17-23 mm long, rhombic to slightly flattened in cross-section, exceedingly sharp (readily drawing blood when shoots grasped!) with a long spine tip. Cones green ripening orange-brown, cylindrical, 7-12 cm long, 4-5 cm broad when open with tightly packed or even congested scales 18-23 mm long and 14-20 mm wide, apex truncated, almost square-ended. Seed 3.5-4 mm, black, with a 10-12 mm wing. (3, 4, 5, 6, and cones in M. P. Frankis collection).

See P. martinezii for differences from that species.

Range

Mexico: SW Chihuahua, W Durango, at 2300-(?)3200 m altitude (5). Each of the 25 populations consists of less than 100 to 350 mature trees (1). USDA hardiness zone 8.

Big Tree

Oldest

Dendrochronology

Ethnobotany

Observations

The Chihuahua/Durango populations are near El Salto in the Sierra Madre Occidental (1).

Remarks

Listed by the WCMC as endangered:"A species known from about 25 sites, containing a few to several hundred trees, often in canyons or on moist north-facing scree slopes. Regeneration is poor and inadequate. A continued decline in the population, especially of seeding trees, is expected." (2).

The foliage is superficially similar to Picea pungens, but the cone is markedly different and shows its alliances are to other species; the most similar in cone are P. martinezii and some species in E Asia, notably P. torano.

Citations

(1) Farjon 1990.
(2) World Conservation Monitoring Centre - Trees.
(3) Taylor, R. J., T. F. Patterson & R. J. Harrod. 1994. Systematics of Mexican Spruce - Revisited. Syst. Bot. 19: 47-59.
(4) Nienstaedt, H. 1983. Picea chihuahuana og Picea mexicana. Dansk Dendrol. Aarsskr. 6: 53-66.
(5) Gordon, A. G. 1968. Ecology of Picea chihuahuana Martinez. Ecology 49: 880-896.
(6) Martínez, M. 1953. Las Pinaceas Méxicanas. Instituto de Biología, México City.

This page co-edited with Michael P. Frankis, Dec-1998.


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This page is from the Gymnosperm Database
URL: http://www.geocities.com/RainForest/Canopy/2285/pi/pic/chihuahuana.htm
Edited by Christopher J. Earle
E-mail:earlecj@earthlink.net
Last modified on 2-Jan-99

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