Pseudotsuga menziesii Pinaceae
Douglas-fir soo-do-TSOO-ga men-ZEE-see-i
- Conifer, evergreen tree, 80-200 ft (24-61 m), crown of young trees conical, dense, become broad flat
top with age. Lower branches drooping, upper ones ascending. Buds oval-conical,
apex pointed,. Needles flattened, radially arranged, but may appear 2-ranked, 2-3 cm long,
bright yellow green, groved above, the underside has 2 wide stomatal band; needles are narrowed at the base
into a slender, petiole-like stalk which sits upon a short, oblique leaf cushion. Cones pendant,
woody or semi-woody, 10 cm long, with distinctive 3-pronged bracts ("the two back feet and tail
of a mouse"), light brown, mature in one season.
- Sun. Prefers neutral or slightly acid, well-drained, moist soils.
- Hardy to USDA Zone 5-6 (Pacific Coast type, P. menziesii var. menziesii)
or Zone 4 (Rocky Mountain type, P. menziesii var. glauca) Native
range from Central British Columbia south along Pacific Coast to central California, central Mexico, also
Rocky Mountains to Arizona, Texas. Most important timber species in US.
- The largest of the Pacific Coast type is in Coos County, Oregon, 36 ft (11 m) in circumference and 329 ft
(100 m) high!
- A closely related species, Pseudotsuga macrocarpa, Bigcone Douglas-fir, is native to southern
California, in mountainous areas from Kern County to just north of the boarder with Mexico in San Diego
County. The most obvious visible difference between P. macrocarpa and P. menziesii is the much larger cone of P. macrocarpa.
- menziesii: named after Archibald Menzies (1745-1842), Scottish physician and naturalist who
collected in the PNW.
- Oregon State Univ. campus: large tree in front of Fairbanks Hall, it is over 100 years old. This
tree is absent in a 1892 photo of the building (then called Cauthorn Hall),
but in a 1910 photo it can be seen in front of the building and taller than
the 3rd story.