Chihuahua spruce

Chihuahua spruce
Chihuahua spruce ( Picea chihuahuana ) in Guanaceví in the Mexican state of Durango
Systematics
Order : Conifers (Coniferales) Family : Pine family (Pinaceae) Subfamily : Piceoideae Genre : Spruce trees ( Picea ) Subgenus : Picea Type : Chihuahua spruce
Scientific name
Picea chihuahuana
Martinez

The Chihuahua spruce ( Picea chihuahuana ) is a species in the genus of spruce ( Picea ). It was only discovered by Rigoberto Dueñas in 1942 and identified and described by the Mexican botanist Maximino Martínez .

description

Branch with needles.

The Chihuahua spruce is a medium-sized evergreen tree that reaches heights of 25 to 40 meters and a trunk diameter (BHD = breast height diameter ) of 45 to 99 cm. The growth in thickness culminates at around 85 years of age. Due to its homeland Mexico, the Chihuahua spruce is very heat tolerant. The light gray bark is thin and scaly and flakes off in small round plates 5 to 10 cm in diameter. The narrow, conical treetop consists of a few long branches between many very short branches around the trunk that is just growing. The bluish-blue-green, extremely pointed needles have a length of 17 to 23 mm, a rhombic to slightly flattened cross-section and striking stomatal lines .

The drooping female cones are 7 to 12 cm long and cylindrical. They are green at first and orange-brown when ripe, closed with a diameter of 3 cm and open 4.5 cm. The cones ripen 6 to 8 months after pollination . The black, 3.5 to 4 mm long seeds have a 10 to 12 mm long wing. The thousand grain weight is 3.56 g.

The Chihuahua spruce tolerates a high calcium content in the soil compared to other spruce species

Distribution map

Occurrence

The home of the Chihuahua spruce is in northwestern Mexico in the Sierra Madre Occidental in Chihuahua and Durango . There it occurs in 25 small populations , each containing a few to a few hundred specimens. It grows at altitudes between 2300 and 3200 meters on river banks in mountain valleys in fresh to moist locations.

Picea chihuahuana as a relict endangered species is classified as Endangered (IUCN 2.3) in the IUCN Red List of Endangered Species .

swell

• Christopher J. Earle, Michael P. Frankis: Picea chihuahuana. In: The Gymnosperm Database. Retrieved December 15, 2010 . 
• Alan G. Gordon: Ecology of Picea chihuahuana Martinez. In: Ecology. Volume 49, No. 5, 1968, ISSN  0012-9658 , pp. 880-896.

Individual evidence

1. ↑ Picea chihuahuana in the IUCN Red List of Threatened Species . Listed by: Conifer Specialist Group, 1998. Retrieved December 15, 2010.

Web links

Commons : Chihuahua Spruce  - Collection of images, videos, and audio files