Delbert Hunter Arboretum and Botanical Garden

Abies concolor, the white fir, concolor fir, or Colorado fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America, including the Cascade Range and southern Rocky Mountains, and into the isolated mountain ranges of southern Arizona, New Mexico, and Northern Mexico. It naturally occurs at elevations between 900 and 3,400 metres (3,000 and 11,200 ft).

It is popular as an ornamental landscaping tree and as a Christmas tree.

Description

This large evergreen conifer grows best in the central Sierra Nevada of California, where the record specimen was recorded as 74.9 metres (246 feet) tall and measured 4.6 m (15 ft) in diameter at breast height (dbh) in Yosemite National Park. The typical size of white fir ranges from 25–60 m (82–197 ft) tall and up to 2.7 m (8 ft 10 in) dbh. The largest specimens are found in the central Sierra Nevada, where the largest diameter recorded was found in Sierra National Forest at 58.5 m × 8.5 m (192 ft × 28 ft) (1972); the west slope of the Sierra Nevada is also home to the tallest specimen on record, 78.8 m (259 ft) in height.[5] Abies concolor subsp. concolor (Rocky mountain white fir) rarely exceeds 38 m (125 ft) tall or 0.9 m (3 ft) dbh. Large (but not huge) trees in good soil range from 40 to 60 m (130 to 200 ft) tall and from 99 to 165 centimetres (39 to 65 in) dbh in California and southwestern Oregon and to 41 m (135 ft) tall and 124 cm (49 in) dbh in Arizona and New Mexico. The dead tree tops sometimes fork into new growth.

The gray bark is usually at least 10 cm (4 in) thick, and brown-hued inside. The leaves are needle-like, flattened, 2.5–8 cm (1–3+1⁄8 in) long and 2 millimetres (3⁄32 in) wide by 0.5–1 mm (1⁄64–3⁄64 in) thick, green to glaucous blue-green above, and with two glaucous blue-white bands of stomatal bloom below, and slightly notched to bluntly pointed at the tip. The leaf arrangement is spiral on the shoot, but with each leaf variably twisted at the base so they all lie in either two more-or-less flat ranks on either side of the shoot, or upswept across the top of the shoot but not below the shoot.

The cones are 6–12 cm (2+1⁄4–4+3⁄4 in) long and 4–4.5 cm (1+5⁄8–1+3⁄4 in) broad, green or purple ripening pale brown, with about 100–150 scales; the scale bracts are short, and hidden in the closed cone. The winged seeds are released when the cones disintegrate at maturity about 6 months after pollination.

White fir can live over 300 years.