Pinaceae Abies durangensis var. coahuilensis (I.M.Johnst.) Martínez
Etymology
Abies refers to ‘to rise’; indicating large trees.
durangensis refers to the Mexican state Durango.
coahuilensis refers to the Mexican state Coahuila.
Colloquial Name
Coahuila fir
Description
These trees grow between 30 and 40 meters tall, with a straight, column-like trunk that often remains bare of branches in its lower half. The crown is either narrowly pyramidal or more rounded in shape. The bark is smooth and greyish or reddish-brown when young, darkening to blackish brown with deep fissures at the base as the tree ages.
The main branches are long and spread horizontally, while the smaller secondary branches either spread outward or angle slightly upward. The twigs are firm, slender, and dark purplish-red or reddish-brown, turning brown with age. They have prominent ridges and grooves between the needle attachments and are densely covered in fine hairs. The scars left by fallen needles are rounded or slightly oval.
The buds are small, oblong, and about 4 to 5 mm long. They are covered in sticky resin, making them appear dark brown beneath a yellowish layer of dried resin. These bud scales persist for two to three years before falling off. The needles are arranged in a spiral along the twigs, with most spreading outward in a comb-like pattern. They may curve slightly forward or backward, and on cone-bearing branches, they either spread similarly or angle weakly upward. They range from 1.4 to 3 cm long and are narrowly linear, tapering to an acute or slightly rounded tip. Their base is slightly twisted, and their color varies from dark green to light green. The lower surface has two distinct bands of stomata that are either as wide as or narrower than the central midrib, while the upper surface has few or no stomata.
The pollen cones grow on the sides of branches, emerging from the bases of the needles. They are about 1 to 2 cm long, though some sources suggest they might be shorter when immature. They are covered in small, resinous protective scales, and the pollen-producing structures are red. The seed cones grow upright on very short stalks. They have a cylindrical shape with a rounded tip and measure between 5.5 and 10 cm long and 3 to 4.5 cm wide. When young, they are pale brown or ochre-colored, maturing to a light brown shade. After the seeds are released, the central cone stalk remains on the tree as a narrow, cone-shaped structure.
The scales that make up the cone are fan-shaped and wider than they are long, typically measuring 1.5 to 2 cm long and 2 to 2.8 cm wide in the middle of the cone. Their surface is smooth but may have fine hairs on the exposed parts. The upper edges are slightly curved backward, while the base narrows into a small stalk. The bracts inside the cone are narrow and spade-shaped, with short, pointed tips, measuring 1 to 1.5 cm long. They remain hidden inside the cone.
The seeds are wedge-shaped, about 7 to 8 mm long, and yellowish-brown. Each seed has a broad, pale yellowish wing that measures 8 to 10 mm long and 6 to 8 mm wide, helping it disperse in the wind.
Subordinate Taxa
There exist 2 subordinate taxa for Abies durangensis:
Distribution
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Habitat
The natural habitats for Abies durangensis var. coahuilensis are temperate forests. It is naturally found at an elevation of at least 3600 up to 3600 metres. Other conifers associated with Abies durangensis var. coahuilensis are:
USDA Hardiness zone – 8
Abies durangensis var. coahuilensis is hardy to USDA Zone 8 (Bannister & Neuner, 2001), meaning its frost tolerance lies somewhere in the range of -12.2C (10F) to -6.7C (20F).
Species Continuity
The population trend for Abies durangensis var. coahuilensis is unknown. There are ongoing threats for Abies durangensis var. coahuilensis and they are listed as follows:
IUCN Category – VU
According to the IUCN Red List, Abies durangensis var. coahuilensis has been assigned the status of VU(Vulnerable). This means that according to the Red List criteria, this species qualifies as Vulnerable and is of risk.
Superordinate Taxa
The nearest superordinate taxon for Abies durangensis is Sect. Grandis. The coordinate taxa for Abies durangensis are therefore:
Abies durangensis var. coahuilensis is further placed under Abietoideae. Abies durangensis var. coahuilensis is also placed under Pinaceae.
This map shows botanical records (points) for this taxon. By opening the map’s sidebar (collapsed by default) you can toggle visibility or change the basemap. By clicking on records, you reveal more information.
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