This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Evergreen trees or shrubs. Leaves needle-shaped or slightly flattened and linear, never clustered. Male cones or catkins axillary. Female cones terminal or lateral, pendulous or erect, with thin closely imbricated scales not thickened at the tip. Seeds usually winged. The species included under this head differ considerably in habit and foliage and position of the cones, and by some authors they are divided into three genera; but the long series of species now known exhibit every gradation of the supposed distinctive characters. Nevertheless, for broad distinctions of groups some of these features are useful.
Some authors go even farther and unite this with Pinus, and include cedrus, Larix, etc. The species are confined to the northern hemisphere, and especially abundant in the temperate, less common in the arctic and warmer regions. The derivation of the generic name is obscure.
§ 1. Leaves needle-shaped or linear, scattered all around the shoots. Cones pendulous when mature. - Abies and Tsuga.
1. A. excilsa (fig. 217). Norway Spruce or Spruce Fir. - This handsome hardy evergreen tree is unsurpassed in the rich warm hue of its dense dark green foliage and the regularity of its pyramidal or conical outline. It is as familiar as our commonest native trees, and therefore we are justified in passing-it by without description. There are numerous varieties, a few of which are very remarkable and worthy of a place in even a small collection. The most curious and interesting are as follows : - Clanbrasiliana, a dwarf slow - growing spreading densely - branched shrub with short closely-packed leaves, never exceeding 3 or 4 feet in height; pygmaea, or nana, is a still more diminutive form, about a foot high; pendula has graceful drooping branches; in-verta has pendulous branches and larger foliage than the type; monstrosa has very stout branches and large foliage; pyra-midalis is a slow-growing dwarf variety of conical shape; and horizontalis is of irregular dwarf habit with long trailing branches. We have by no means exhausted the list of varieties, but this enumeration will be sufficient for all but collectors. The Common Spruce is found in the mountain valleys of Central and the plains of Northern Europe and Asia.
Fig. 217. Abies excelsa.
2. A. alba. White Spruce. - A handsome compact-growing small tree 50 to 70 feet high, resembling the Common Spruce, but with shorter thicker less sharply pointed pale glaucous green leaves, and small cylindrical cones from 1 to 2 inches long. Scales of the cone entire. A native of Canada and other parts of North America. The variety minima is an extremely diminutive plant of globular form. It is the echino-formis of French gardens. The varieties glauca and caerulea differ merely in the tint of the foliage.
3. A. nigra. Black Spruce. - This species has the small cones of the last species, but the scales are irregularly toothed at the margin. The foliage too is of a deep dark green colour. Neither this nor the last equal the Common Spruce as an ornamental tree, for they both lose their beauty as they grow old. A. rubra, Red Spruce, is a variety of this with redder bark and cones. Both occur in the northern parts of North America.
A. obovata and A. orientalis are two closely allied species or forms of one species, the former from Siberia, and the latter from the countries bordering the Black Sea. They are remarkable for their compact habit and small slender foliage, and loose cones from 2 to 3 inches long. The latter is sometimes found under the alias of Wittmaniana and is a slow-growing handsome tree.
4. A. Menziesii. - This is a tree from 50 to 70 feet or more high with very rigid slender divergent crowded mucronate leaves about an inch long, bright green above, glaucous beneath. Cones about 3 or 4 inches long. Scales thin, oblong, toothed. A very hardy species, not so ornamental as some others on account of the early loss of its leaves. Northern California.
5. A. Smithiana, syn. A. Morinda. - A large tree with graceful drooping branches densely clothed with rigid sharply mucronate bright green leaves from 1 1/2 to 2 inches long. Cones from 4 to 6 inches long, with broad entire rather thick shining brown scales. This is a native of the mountains of Northern India, China, and Japan. Unlike many of its class, this tree increases in beauty with size, and on the same soil and in the same situation it gradually assumes a beautiful form from the most wretched-looking specimens. This is due to its being Spring-tender as a small plant.
There are several Japanese species of somewhat recent introduction we may mention here: A. firma, A. microsperma, A. Alcoquiana, and A. Jezoensis. The hardiness of some of these species has not yet been proved.
6. A. Dougldsii. - This is a magnificent and very lofty tree in its native habitat, where it occasionally attains a height of 300 feet. Leaves flexible, spreading, in two ranks, flat, linear, scarcely pointed, bright glossy green above, and more or less glaucous beneath, from 1 to 1 1/2 inches- long. Cones about 3 inches long, with broad rounded scales and conspicuous projecting deeply-toothed bracteoles. A native of North-western America, introduced about the year 1826. Unfortunately, this beautiful ornamental tree, though perfectly hardy, will not flourish in an exposed situation, or the immediate vicinity of the sea. It is a fast-growing species, with somewhat pendent symmetrically disposed branches and reddish brown shining bark. The variety taxifolia is of smaller growth, with longer darker green leaves; and Standishiana has large glossy dark green leaves distinctly silvery below.
7. A. Canadensis. Hemlock Spruce. - This is a very distinct species and very beautiful as a small tree. In its native country it grows from 50 to 80 feet high, with slender pendulous branches. Leaves linear, flat, obtuse, about 6 lines long, dark green above, silvery beneath. Cones less than an inch long, with oblong rounded entire scales. An extremely elegant hardy evergreen, flourishing well in damp situations. North America.