Abies concolor / white fir

Abies concolor, as described in 1861 by (Gordon and Glendinning) William (Wilhelm) Hillebrand (1821–1886),in Verhandlungen des Naturhistorischen Vereines der Preussischen Rheinlande und Westphalens, 18th edition, is commonly known as white fir, Colorado white fir, or Rocky Mountain white fir; as well as abeto del Colorado, or pino real blanco in the Spanish language. The species name, "concolor," means "same color" in the Latin language, referring to needles having the same color on the adaxial and abaxial sides.

Ethnobotany. White fir is a preferred construction species because of its nail-holding ability, lightness in weight, and resistance to split, twist, and pitch. It is straight-grained, non-resinous, fine-textured, stiff, and strong.

White fir is popular as a Christmas tree and for Christmas decoration owing to its soft needles, generally excellent needle retention and abundance. It is often marketed as concolor or white fir.

artwork by John Muir
artwork by John Muir

Description. White fir is an evergreen coniferous tree which grows to mature heights of 130 feet (40 m) tall and with a trunk 35 inches (90 cm) in diameter, measured at breast height.

  • Crown is spire-like.
  • Bark is gray, thin, and smooth, thickening with age to 3.2 inches (8 cm) and breaking into deep longitudinal furrows, often revealing yellowish inner periderm, which may appear 'corky.'
  • Branches diverge from trunk at right angles, the lower often spreading and drooping in age; twigs are mostly opposite, glabrous or with yellowish pubescence.
  • Buds are exposed at the branch tips, either yellowish in color and nearly conic in shape (when large) or brownish and nearly globose (when small). They are resinous, with a rounded to pointed apex. Their basal scales are equilaterally triangular, glabrous, not resinous, with entire margins and a sharply pointed apex.
  • Foliage is needle-like, 0.6 to to 2.5 inches (1.5 - 6 cm) long, mostly double-ranked, flexible, with a straight proximal portion. They have a flat cross section, and sometimes slightly grooved. When crushed, the needles have a pungent, frequently camphor-like odor.
  • Pollen cones at the time of pollination are red, purple, or green in color.
  • Seed cones are cylindrical, 2.8 to 4.8 inches (7 - 12 cm) long and 1.2 to 1.8 inches (3 - 4.5 cm) broad, olive-green in color.
  • Seeds are 0.3 to 0.5 inch (8 - 12 mm) long with a tan body and tan wing with rosy tinge about twice as long as the body.
natural range of <em>A concolor </em>var. <em>concolor </em>in green and var. <em>lowiana </em>in Blue.
natural range of A concolor var. concolor in green and var. lowiana in Blue.

Distribution. This species is native to USA — the states of Idaho, Oregon, California, Nevada, Utah, Colorado, New Mexico, and Arizona as well as Mexico — Baja California Norte and Sonorawestern, growing at elevations of 3,000 to 10,000 feet (920 - 3050 m) above sea level.

Hardy to USDA Zone 4 — cold hardiness limit between -30° and -20°F (-34.3° and -28.9°C).

Abies concolor — a closeup of needles and seed cones.
Photo by USDA Forest Service - public domain photo
Abies concolor — white fir and trembling aspen stands, northern U.S.
Photo by Chris Earle
Abies concolor — the Summerland Ornamental Gardens, Summerland, B.C., Canada
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — white fir in its native habitat, North Rim, Grand Canyon, Arizona, U.S.A.
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — North Rim, Grand Canyon, Arizona, U.S.A.
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — long, blue-green flat needles
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — long, blue-green flat needles
Photo by Blake Willson, courtesy of TreeLib.ca

Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — close-up of needles
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — unique circles found in Abies species where needles were attached to twigs.
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — mature cone in the fall. Photo from the Denver Botanic Gardens.
Photo by Blake Willson, courtesy of TreeLib.ca
Abies concolor — Furrowed bark of older Abies concolor trunk
Photo by Blake Willson, courtesy of TreeLib.ca

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