Kingdom: Plantae

Phylum: Coniferophyta -- conifers

Class: Pinopsida

Order: Pinales

Family: Pinaceae -- pine

Variety: Two varieties are generally recognized, var. glauca having shorter cones (4-7 cm long) with the bracts more spreading and often reflexed and the needles blue-green, mostly in the interior northwest, and var. menziesii having longer cones (6-10 cm) with the bracts more straight and appressed and the needles greenish-yellow, mostly along the Pacific coast. The two varieties do intergrade and are sympatric in portions of northeastern interior Washington and southern British Columbia.

Common Name: Douglas fir

Species Code: PSME

Origin: A very common tree native to lower elevation forests of western North America from British Columbia to California and east to Alberta and New Mexico. While primarily a forest species, it is found in scattered stands on some of the buttes around the Palouse.

Rare: no

Form: tree, coniferous, to 90 meters tall, young crown conic, becoming rounded with age; bark thick, rough, dark brown; branches spreading to drooping; twigs slender and pubescent, becoming glabrous with age; leaf scars slightly raised above twig surface; buds non-resinous, fusiform, to 15 mm long, reddish brown.

Mature height: to 300 feet

Duration: perennial

Longevity: long

Habitat Type: forest

Wetland Indicator Status: FACU

Leaves: needles persistent 7-10 years, mostly 2-3 cm long, obtuse to acute tipped, yellow-green to dark green for var. menziesii or bluish green for var. glauca, the lower surface with a row of white stomata on each side of the midvein.

Flowers: the conifers are gymnosperms and do not have flowers in the traditional sense.

Anthesis: spring

Fruit: staminate cones yellow to reddish, 6-10 mm long; pistillate cones 4-10 cm long, pendent, yellowish to purple, maturing to brown and soon deciduous, scales stiff, with an exserted 3-lobed bract, the middle lobe longer than the others; seeds 5-6 mm long, broadly winged; cotyledons mostly 5-8.

Characteristics:
Reproduces sexually by seed.
Seedlings are shade intolerant and cannot establish under the canopy of other trees.
P. taxifolia in St. John 1963 and in Davis 1953. P. mucronata in Piper & Beattie 1914.
42,080 seeds/lb (USDA NRCS PLANTS Database 2010).
46,191-46,762 seeds/lb for 3 eastern Washington sources (Stein & Owston undated).
2n=26 (Hitchcock et al 1969, Flora of North America Editorial Committee 1993, Baldwin et al 2004).
Diploids only are known.
Wind pollinated.
Plants are monoecious.
The conifers are gymnosperms and do not have flowers in the traditional sense. Instead, the male and female reproductive parts are borne in separate strobili (cones) on the same tree. The male cones drop from the tree soon after the pollen is released.
Seeds are windborne for short distances.
Native peoples used the wood for construction, tools, and fuel. Various plant parts also were used medicinally.
One of the most important lumber species.
Trees provide cover and habitat for many species. Small mammals and birds eat the seeds. Twigs and needles are browsed by deer.
Minor browse for Rocky Mountain elk in winter and spring, more important browse in fall (Kufeld 1973).
Gail (1921) measured climatic differences on north and south facing slopes of Paradise Ridge and Tomer Butte in relation to occurrence of P. menziesii. He concluded that higher evaporation and transpiration rates prevented seedling from establishing on south facing slopes.

Comments:
Because P. menziesii is an important timber species, there is a large volume of information in the scientific and popular literature. Since P. menziesii is a minor constituent of the Palouse Prairie, we have not attempted a thorough review or presention here. The following, however, are a few references of particular note.
Hermann & Lavender 1990.
Turesson 1914.

Sun requirement: full sun to partial shade

Soil moisture: mesic

Precipitation: 18-100 inches (USDA NRCS PLANTS Database 2010).

Fire: Killed by fires which reach the crown. Older trees have thick bark and can survive low intensity fires in the understory (Steinberg 2002).

Sowing time: fall

Transplant time: spring

Stratification: cold moist

Seed yield: high

Seed harvest: difficult

Seed cleaning: medium difficulty

Planting duration: long

Seed shatter: low

Seed size: large

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native upland tree

Alternate Species: taxifolia, mucronata

Propagation:
Reproduces sexually by seed.
5 protocols in the Native Plant Network
University of Kentucky
1+0 bareroot, J. Herbert Stone Nursery, Oregon
2+0 bareroot, J. Herbert Stone Nursery, Oregon
container stock, J. Herbert Stone Nursery, Oregon
Glacier National Park, Montana

Notes: An excellent and widely used landscape tree.

References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 3/1/10 online at http://ucjeps.berkeley.edu/interchange.html

Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 7+ vols. New York and Oxford. Oxford University Press. Online at http://www.fna.org/FNA/

Gail, Floyd W. 1921. Factors Controlling the Distribution of Douglas Fir in Semi-Arid Regions of the Northwest. Ecology 2:281-291.

Hermann R.K., and D.P. Lavender. 1990. Pseudotsuga menziesii (Mirb.) Franco, Douglas-fir. In Burnes, R.M., and B.H. Honkala (eds.). Silvics of North America. Volume 1. Conifers. Agriculture Handbook 654. Washington, DC: U.S. Department of Agriculture, Forest Service. pp.527-540.

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Kufeld, Roland. 1973. Foods Eaten by the Rocky Mountain Elk. Journal of Range Management 26:106-113.

Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Press of the New Era Printing Company, Lancaster, PA. 296 pp.

Stein, William I., and Peyton W. Owston. undated. Pseudotsuga Carr. Douglas-fir. In: Bonner, Franklin T., and Rebecca G. Nisley (eds.). Woody Plant Seed Manual. USDA Forest Service. Available online at http://www.nsl.fs.fed.us/wpsm/

Steinberg, Peter D. 2002. Pseudotsuga menziesii var. glauca. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/[accessed 3/1/10].

St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA.

Turesson, Gote. 1914. Slope Exposure as a Factor in the Distribution of Pseudotsuga taxifolia in Arid Parts of Washington. Bulletin of the Torrey Botanical Club 41:337-345.

USDA NRCS. 2010. The PLANTS Database (http://plants.usda.gov, 1 March 2010). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Links:
Plant Profile from the USDA PLANTS Database
Species account for P. menziesii var. glauca from the Fire Effects Information System
Species account for P. menziesii var. menziesii from the Fire Effects Information System
Species description from Flora of North America
Species information from the University of Washington Herbarium
Plant Guide from the USDA PLANTS Database