Spruces are evergreen trees with pyramidal habits, whorled branches, and scaly bark. Buds are small and ovoid or conical in outline. Buds may or may not be resinous. Leaves are spirally arranged. Needles are usually four-sided with stomatic lines on all sides. Flowers are monoecious. Fruit is a pendant cone with numerous, persistent scales.
Picea pungens–Colorado Spruce
| A. | Scales on terminal winter buds are rounded and emarginate (shallow notch) or indented at the tips, especially those near the bud tip. Leaves are usually glaucous and terminate in rather abrupt, but not sharp, points. Needles have a disagreeable odor when crushed. Fruit is less than 11/2 inches (4 cm) long. | |
| Picea glauca (canadensis, alba)–White Spruce | ||
| AA. | Scales on terminal winter buds are more pointed and not emarginate at the tip. Leaves are more tapered than white spruce but not sharply pointed. Foliage is dark green and not glaucous. Branch tips are pendulous, as are cones which are 4—6 inches (10—15 cm) long. | |
| Picea abies (excelsa)–Norway Spruce |
Norway Spruce–Picea abies (excelsa)
Norway spruce is one of the most commonly planted European evergreens and was a favorite among early pioneers for plantings around homesteads. It is extensively planted in Ohio as a windbreak and for Christmas trees, though cut Norway spruce trees do not retain their foliage as well as blue or white spruce. A valuable tree for reforestation purposes on heavy, moist, clay soils of northern Ohio, the Norway spruce may escape further north and destroy native populations of native white spruce. It is the largest and longest-lived spruce for Ohio gardens.
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| Norway Spruce | ||
Leaves diverge from the stem at nearly right angles but in a flatter arrangement than blue spruce. Viewed from the end of the stem, the foliage is more semicircular. Leaves are more tapered than white spruce but not sharply pointed. Foliage is 1/2 inch (13 mm) long, dark green, and not glaucous. Scales on the terminal winter buds are more pointed and not emarginate at the tip. Flowers are monoecious and open in May. Cones are pendulous and 4—6 inches (10—15 cm) long. The cone of the Norway spruce is the largest of all the spruces and is an excellent identification feature when present.
This exotic is a large, graceful tree with reddish-brown bark and heavy, spreading branches. The branches are pendulous, or drooping, and often touch the ground. Norway spruce retains lower foliage longer than do either the blue or white spruce. The dark green foliage is quite handsome and resistant to spruce mite.
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| White Spruce |
White Spruce–Picea glauca (canadensis, alba)
White spruce is a native tree of the lake states and the New England region and extends north to the Canadian tundra. It is a large tree, ranging from 60—90 feet in height, but very narrow, or upright, when mature.
The needles are blue to light green and sometimes nearly white. Foliage is not as sharp as blue spruce and has a striking, pungent odor when crushed. Leaves diverge from the stem at nearly right angles but in a flatter arrangement. Viewed from the end of the stem, the foliage is more semicircular than circular. Scales on terminal winter buds are rounded and emarginate at the tips. Flowers are monoecious and bloom in May. Fruit is less than 1 1/2 inches ( 4 cm) long and matures in the fall.
White spruce are planted in Ohio for screens and windbreaks. In addition, the white spruce is both grown and shipped into Ohio as Christmas trees. Foliage does not hold as well when cut as do the firs and the blue spruce. White spruce is sensitive to spruce mite and high temperatures in Ohio and has a shorter life span than the blue or Norway spruces.
Colorado Spruce (Blue Spruce)–Picea pungens
This native of the Rocky Mountains is one of the best-known evergreens and is commonly planted for landscape purposes in Ohio. Colorado spruce has a splendid conical form for use as a lawn specimen. Height rarely exceeds 30—50 feet and the distinctive, bluish-silvery-foliaged types are the most valuable for ornamental purposes.
Foliage is green, silver, or steel blue and sharp enough to draw blood. Foliage color varies with the seedling or variety. Leaves on 1-year-old twigs are rigid and spread from the twig in all directions. Needles are borne at nearly right angles to the stem. When viewed from the end, the foliage is in a circular pattern. Brownish-yellow bud scales curve outward and are often rolled at the apex. Flowers are monoecious and bloom in May. The pendulous cone is about 2—3 inches (5—7 1/2 cm) long and matures in the fall.
The Koster's blue spruce is one of a number of varieties selected for its foliage color and is propagated by grafting upon seedlings of Colorado spruce or other spruce species. Using the proper seed sources will increase the number of blue seedlings in the population. Colorado spruce is also grown as a premium Christmas tree and holds its needles well after being cut. Blue spruce is well-adapted to the heavy, clay soils of Ohio, and loss in the landscape is often due to windthrow.
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| Colorado (Blue) Spruce | ||