A tree 80 to 100 ft high in nature; young shoots yellowish, patched with minute down, or glabrous; buds very resinous, egg-shaped, rounded at the top. Leaves glaucous green, 1 to 3 in. long, 1⁄12 to 1⁄10 in. wide; tapered at the base, rounded (with sometimes a slight notch) at the apex; otherwise of even width, not grooved above. There are not very conspicuous lines of stomata on both surfaces; they cover the whole centre of the leaf above, but beneath they are in two bands. The leaves are mostly aggregated into two opposite sets, but on the upper side of the branchlet there are a number of leaves pointing upwards, and beneath some pointing downwards; the arrangement therefore is irregular, and the upper leaves are considerably the shorter. On cone-bearing shoots the leaves generally are shorter and stouter and curve upwards. Cones about 4 in. long, 11⁄2 to 13⁄4 in. wide, of a rich plum colour, as I have seen them in Waterers' nursery at Knap Hill, turning brown with age; bracts enclosed by the scales.
Native of Colorado, Arizona, New Mexico, and Utah (but see var. lowiana); discovered in 1847 and introduced in 1872. It is one of the most beautiful of all conifers and grows almost as well in southern England as it does in the moister and cooler parts of the country. The best recorded are: Cragside, Northumb., 131 × 111⁄2 ft (1958); Benmore, Argyll, 131 × 91⁄2, 128 × 111⁄4, and 124 × 93⁄4 ft (1956); Blair Atholl, Perths., 127 × 93⁄4 ft (1955); Eridge Castle, Kent, 118 × 111⁄4 ft (1963). There are also big trees at Westonbirt and Batsford, Glos., and at Dropmore, Bucks.
f. violacea (A. Murr.) Beissn. – This name applies in general to trees with leaves of a particularly silvery-glaucous tinge; such forms occur in nature and in seed-beds.
cv. 'Wattezii'. – Leaves silvery-yellow when young; of Dutch nursery origin.
var. lowiana (Gord.) Lemm. A. lowiana (Gord.) A. Murr.; Picea lowiana Gord. – As seen in gardens, this fir is well distinguished from cultivated specimens of A. concolor and indeed has long been grown as a distinct species. The distinguishing characters of the “A. lowiana” of reference books are found mainly in the foliage: the middle line of erect leaves seen in 'typical' concolor is absent, the leaves lying pectinately in one plane, or directed upward and outward in a V-shaped arrangement. It is also said to have a separate area of distribution, being confined to the ranges near the Pacific, from Oregon into the Sierra Nevada (cf. the distribution of A. concolor). However, American botanists are for the most part reluctant to concede even varietal status to this fir, preferring to regard it as a phase of A. concolor, included within the natural span of variation of that species. Here, following the Kew Hand-list, it is treated as a variety.
A. F. Mitchell of the Forestry Commission has observed that the trees cultivated in this country are of two forms. The first has a rectangular crown, is often forked, and has a dark, not markedly corky bark; its leaves recall A. grandis, being flatly arranged, long, and quite green. These are likely to have originated from Oregon. The second form, probably from the Sierra Nevada, approaches A. concolor as seen in cultivation; it is conical-crowned, forks only at a great height, and has a thick, corky, paler brown bark; leaves partly assurgent, bluish green, with stomatal bands above.
This variety, if such it be, has attained a good height in cultivation. For the most part, the best specimens are in areas of high rainfall but the thriving tree in the National Pinetum, Bedgebury, Kent, suggests that it is a fairly amenable fir. This tree is of the second form described above; planted 1925 it measured 86 × 9 ft in 1965. Of this form the two best recorded are: Durris House, Kinc., 145 × 141⁄4 ft (1955), and Bodnant, Denbigh, pl. 1886, 133 × 111⁄2 ft (1966). Others of 125 ft and over are at Dupplin, Perths.; Cragside, Northumb.; Oakley Park, Shrops.; and Westonbirt, Glos. The first form, with the “grandis” type of foliage (see above), is represented by trees of 115 ft and over at Rammerscales, Dumf.; Monk Hopton, Shrops.; and Brockhall, Northants. Two others of this form whose planting dates are known are: Youngsbury, Herts., pl. 1866, 108 × 7 ft; and Castle Milk, Dumf., pl. 1886, 113 × 9 ft (both 1966).
Cultivated trees considered to be hybrids between A. concolor and A. grandis have been reported from Belgium and Germany.