General: Pine Family (Pinaceae). Native evergreen trees growing to 75-100 meters tall, the crown conic, becoming round or straggly with age, branches dropping, twigs mostly opposite. Bark: smooth, gray, becoming brown and furrowed with age. Needles are 2-6 cm long, flattened, strongly waxy and silvery-white on the lower surface, green above, mostly 2-ranked, spreading horizontally, not concealing the upper surface of twigs, the needles 1-ranked and spiraled higher on the tree; resin canals marginal, located near the lower epidermis; stomatal rows absent on the upper surface at midleaf, 5-7 stomatal rows on each side of midrib of lower surface. Seed cones: 6-12 cm long, 2-4 cm wide, dark purple or blue to gray or light green at maturity, erect and on the upper branches. Native. The common name refers to the large size of mature trees, one of the tallest of the firs.
Variation within the species: Although Abies grandis is fairly uniform throughout its range, a green coastal form and gray interior form are often recognized, and five fairly distinct climatic forms of grand fir have been identified, differing mainly in physiological and ecological traits. Abies grandis var. idahoensis Silba was recently described (Silba 1990) as “an inland variety, to 1850 m altitude” from southeast British Columbia to central Idaho, characterized by smaller cones, a distinct forward and vertical spread of the leaves, and more twisted petioles. In southern Oregon and northern California, grand fir hybridizes and introgresses with A. concolor, which generally grows in higher, drier habitats. Natural hybrids also are known between grand fir and subalpine fir.
Abies grandis is distinguished from the closely similar A. amabilis by bud scales slightly pubescent or glabrous (vs densely pubescent), upper surface of twigs easily visible (vs concealed by the needles), and variably colored mature seed cones (vs purple). Compared to subalpine fir, grand fir occurs at lower elevations, has a wider crown, and usually produces broad spreading lower limbs with beautifully even secondary branchlets.
Distribution: Coastal British Columbia, south along the coast to Sonoma County, California. A disjunct population system in the Northern Rocky Mountains occurs from southern British Columbia and Alberta to Washington, Oregon, Idaho, and western Montana. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
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