Photo Courtesy of Dave Powell, USDA Forest Service, http://www.bugwood.org/
Picea engelmannii Parry ex Engelm.
Scientific Name Synonyms:
Life Span: Perennial
Growth Characteristics: Engelmann spruce is a large tree, averaging 30 inches in diameter and 90 feet in height. The crown in pyramidal, with the top somewhat rounded and limbs extending to near the ground. Branches are in whorls. At very high elevations, the crown becomes distorted or the whole tree may be low and shrubby in appearance (Krumholz). The trees grow rather slowly, reaching mature size in about 150 years, but may live 400 or more years.
Flowers/Inflorescence: Both male and female cones are separate, but on the same tree. The male cones are small and dark purple in color. The female (seed) cones cluster near tree tops and are about 2 inches long, light brown, with papery thin flexible cone scales. The scale tips are wedge-shaped to rounded, with wavy or eroded margins. Cones are all pendulous (hang downward) on the twigs and mature in one season.
Fruits/Seeds: Seeds are small, about 1/8 inch long, nearly black in color with ½ inch terminal wings.
Leaves: Needle-like, about 1 inch long, blue-green in color, stiff, sharp-pointed, and square in cross-section. They arise spirally from the twigs, with those on the bottom side tending to grow upward. Buds are small, up to ¼ inch in length and pale brown in color.
Stems: Twigs are stout, rather shiny, and orange-brown in color. They are covered with peg-like projections (called sterigmata) or leaf bases after leaves have fallen. This causes the twig to feel and appear rough. New growth is sometimes covered with fine short hairs that are visible with a magnifying lens. The bark is thin, seldom exceeding ½ inch in thickness. The surface is comprised of loosely attached red-brown scales that are generally scattered and not divided into ridges and furrows. The wood is good quality, very light in weight, soft, straight grained, and yellowish in color.
Engelmann spruce is found in some of the highest and coldest forest environments in the western United States, characterized by long, cold winters with heavy snowpack and short, cool summers. It extends down to lower elevations along stream bottoms where cold air flows down the valley and collects in localized frost pockets. Generally found on moist and cool sites, but at timberline it may occur on somewhat dry sites. At middle elevations, pure stands are usually found on alluvial terraces, wet benches, bottomlands, slopes with seeps or cold north or east aspects. It occurs on all aspects at timberline, and grows in clumps called tree islands.
Stands of Engelmann spruce will establish themselves under other forest types such as aspen or lodgepole pine because it is shade tolerant.
Soils: Does best in deep, rich, moist soils.
Associated Species: Subalpine fir, white fir, Douglas fir, limber pine, bristlecone pine, and lodgepole pine.
Uses and Management:
Engelmann spruce has been and continues to be an important lumber source in Utah. Since it is found most abundantly at high elevations, it is rather difficult to harvest. In addition to saw timber, this species is used considerably for poles, railroad ties, and mine props. In the past, some has been used for fuel. Many stands have been decimated by the spruce bark beetle in recent years.
Engelmann spruce has no value as a forage species, but the seeds are eaten by several species of small mammals and birds. It does provide excellent hiding and thermal cover for deer, elk, moose, bighorn sheep, and bear.
Native Americans used Engelmann spruce for numerous purposes. The bark was often peeled into sheets and used for making canoes, baskets, and roofing. The fibrous roots were used to make rope, and the boughs and needles to make incense, body scents, and cleansing agents. Various teas and poultices were made from Engelmann spruce for medicinal purposes. Native Americans occasionally ate the inner bark.