Abies concolor (Gord. & Glend.) Lindl. Ex Hildebr.

 

by Kirsten Aamodt, Native Plants Class 2003

Common names: White fir, balsam fir, white balsam fir, silver fir, and pino real blanco

Family: Pinaceae

Synonymy: None.
Etymology: The genus, Abies, is an ancient Latin name for tall tree and translates to “rising one” (1).  The specific epithet refers to the similarity of color, as both sides of the needle are a pale blue green.  The common name refers to the color of the bark (9). 

Identification

Growth form: White fir is a coniferous tree achieving heights of 40 m.  Short persistent branches and heavy foliage create a dense crown with a steeple-like effect (4, 6).
Roots: Preferring moist well-drained soils to heavy clays, the rooting is lateral, shallow, gaining depths of 40 in. For this reason white firs are susceptible to windthrow (2, 10, 11).
Stem: The trunk can be up to 90 cm in diameter.  In youth the bark is thin, gray, and smooth.  Resinblisters break the surface.  A pungent, camphor-like scent arises from these “balsam” blisters accounting for the common name, balsam fir.  With age the bark can appear corky and thickens to 18 cm.  Deep longitudinal fissures form and reveal a yellowish inner periderm (5, 6). The lower branches droop while the upper ones diverge from the trunk at 90-degree angles.  The twigs are usually opposite, stout, and smoothly yellowish green ageing to gray.
Leaves: At 1.5-6 cm in length and 2-3 mm in width the leaves of the white fir are unusually long.  The flat, bluntly tipped needles are obscurely arranged in 2 rows on each side of the stem.  Older needles on upper branches curve upwards along the stem plane. The pliable needles are silvery blue or silvery green on both sides with a central whitish line along both sides (4, 5, 8, 11).

Inflorescences/flowers: Non-flowering.
Fruit: Monoecious. Pollen Producing Cones: The male cones are rose colored to dark red, appearing  on the lower branches in the spring and early summer.  Wind currents disperse pollen to the female cones on the upper reaches of the trees followed by the die off of the male cones (7).  Seed Producing Cones: Female cones are sessile, cylindrical, and yellowish to greenish to purple, upright, and 7-12 cm by 3-4.5 cm. In the fall, the fruit matures and the scales, which are broader than they are long, drop off leaving an upright, spike-like central stalk, “a distinguishing feature even in mid-winter” (5). Wind blown seeds have a broad, tan wing that is twice as long as the rosy colored seed.  There are viable seed crops only every 2-3 years with lower than 50% rate of germination (2, 4, 6).

Similar species: In southern Oregon and northern California, Abies grandis (Dougl.ex D. Don) Lindl. at middle elevations resembles and appears to hybridize with the white fir (2, 15).  In Arizona it is easily distinguishable from Abies lasiocarpa (Corkbark Fir) by observing the cork-like bark of the later species; and from Pseudotsuga menziesii (Douglas Fir) by observing P. menziesii's distinctive, pendant cones with their three-pronged papery bracts. 

 

Ecology

Life history: Perennial
Native/introduced: Native to areas with abundant snowfall and long winters at elevations of 1300-3000 meters.  Unlike other firs, A. concolor, requires less moisture and tolerates heat and drought.  Seldom found in pure stands, at elevations below 2600 m it occurs amongst Pseudotsuga menziesii and Pinus ponderosa.  Above 2600 m it occurs with Picea englemannii, and other mixed conifers.  Can also be found at elevations of 1800-2300 m in canyons along perennial streams (4, 6, 12)

Photosynthetic pathway: C3.
Phenology: Evergreen.  Pollen producing cones appear in spring and early summer while the seed producing cones mature in September and October (1).

Distribution: White fir grows in areas that receive at least 20 inches of precipitation annually.  Populations can be found from Canada to California and down into Baja California and northwest Sonora, Mexico.  Locally populations exist in Coconino, Cochise, Pima, and Mohave counties (2, 5, 13). 

 

Uses: Rated as a second grade lumber it is mostly harvested for plywood, pulp, crating and furniture.  Commonly sold as a Christmas tree and as nursery stock.  Seeds provide forage for songbirds, grouse, and small mammals.  Ungulates browse on the foliage.  Porcupines eat the bark.  As far as toxicity goes it can cause a mild dermatitis or eczema. (2, 3, 5).  Aboriginal people had many medicinal uses such as: a decoction of the needles, bark and resin for aid with pulmonary troubles and venereal disease; infusions of foliage to treat rheumatism; and poultices of fresh pitch applied to wounds (13).

 

References

  1. Gledhill, David. 2002. The names of Plants 3rd Edition. Cambridge University Press.
  2. USDA, NRCS. 2002 The PLANTS Database, Version 3.5 (http://plants.usda.gov/factsheet/doc/fs_abco.doc) National Plant Data Center, Baton Rouge, LA. 70874-4490 USA
  3. Zouhar, Kris, 2001(April). Abies Concolor. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire  Sciences Laboratory (2003, October). Fire Effects Information System, [Online]. Available: (http://www.fs.fed.us/database/feis/) [Nov. & Dec. 2003].    
  4. Preston, Richard J., 1961. North American Trees. The M.I.T. Press.
  5. Elmore, Francis H., 1976. Shrubs and Trees of the Southwest Uplands.  Southwest Parks and Monuments Association.
  6. Morin, Nancy R., convening editor. 1993. Flora of North America Volume 2, Pteridophytes and Gymnosperm. N.Y. Oxford University Press.
  7. Epple. Anne Orth. 1995. A Field Guide to the Plants of Arizona. The Globe Pequot Press.
  8. Department of Botany. Rheinische Friedrich-Wilhelms-University Bonn, Germany (http://www.botanik.uni-bonn.de/conifers/pi/ab/concolor.htm)
  9. Estes, John. Treeguide from Athenic Systems, The Outdoor Management Company. (http://www.treeguide.com)
  10. Evans, Erv. 2000-2003. N.C. State University. Native Plant Fact Sheet (http://www.ces.ncsc.edu/depts/hort/consumer/factsheets/trees-new/abies_concolor.html)
  11. De Gomez, Tom & Bailey, John Duff. 1998. Beyond Ponderosa. Flagstaff Community Tree Board.
  12. Brown, David E., editor. 1994. Biotic Communities Southwestern United States and Northwestern Mexico. University of Utah Press.
  13. Kearney, Thomas H., Peebles, Robert H., 1961. Arizona Flora 2nd Edition. University of California Press.
  14. University of Michigan. Native American Ethnobotany. (http://herb.umd.umich.edu)
  15. Pojar, Jim, Makinnon, Andy, editors. 1994. Plants of Coastal British Columbia Including Washington, Oregon and Alaska. Lone Pine Publishing.