The pine-family has many species in about all parts of the earth. In this connection only a few of the hardiest and handsomest can be referred to. The white pine (Pinus strobus) of Iowa and western Wisconsin is adapted to prairie planting, and it has better form and a denser habit for Eastern planting. As obtained from any point east of the lakes, it fails to endure the dry hot air of the corn-growing belt.
The red pine (Pinus resinosa) is a favorite for Northern and Western planting. Its form of top and thick clusters of slender, soft, dark-green and long leaves fit it specially for ornamental planting East or West. But the Eastern type is not hardy on the prairies.
The yellow or bull pine (Pinus ponderosa) as obtained in the Black Hills of South Dakota stands every exposure at the North and West, is quite rapid in growth, with rounded conical top and a bold expression that fits it specially for picturesque parts of the grounds. As obtained from Colorado the tree is more open, and as it attains age it loses its regularity of outline.
Of the foreign species, Pinus laricio is extremely variable in hardiness as obtained from different parts of Europe. Even the variety known as Austriaca or Austrian pine is variable, as grown from seed, in habit of growth, color of foliage, and hardiness as grown in the West. Its harsh leav,es are not suitable for small places. But it is one of the best for parks and large places. The stone pine (Pinus cembrd) from the plains of east Europe is hardy anywhere in the East or West. It is much like our white pine in shade of color of foliage, but it is far more compact in form and is pyramidal in habit. As obtained from west Europe it is not hardy at the West.
The type of Scotch pine (P. sylvestris) from east Europe known as Riga pine is hardy at the West, and is more ornamental east of the lakes than the trees grown from seed gathered on the sandy tracts of Alsace, France. Its bluish shade of color of foliage fits it for planting at points to which attention is to be directed.
The Swiss mountain pine (Pinus montana) is extremely variable in habit. The most valuable type at the West is P. pumilio. It is a handsome low-spreading shrub, with dark-green foliage that varies little in color in the drought of summer or the cold of winter. It is specially valuable for corners and angles of lawns, walks, and drives. Several other varieties of varying heights and habits of growth are valuable east of the lakes.
330a. The Hemlock. - The hemlock (Tsuga Canadensis) is also variable in its adaptation to varied climates and soils. As obtained in northwestern Wisconsin it has proven hardy and very beautiful in the prairie States in situations where sheltered from the westerly winds, while plants from western New York have been withered during the first year of growth. The Northwest type also endures drought on high ground, while the Eastern type only succeeds on moist ground. The hardy type is admirably suited for ornamental screens, and can also be used to advantage as single specimens.
330b. Arbor Vitae. - The American arbor vitae (Thuya occidentalis) is admired in landscape work when young, but as it attains some age it changes the character of its leaves, becomes irregular in habit, and loses its lower branches.
The Eastern nurseries describe several beautiful varieties which do well at the East, but they are not favorites at the West. The best varieties for Eastern use are Siberica, pyramidal, globosa, and the golden.
The most popular use of these varieties is for ornamental screens or hedges east of the Great Lakes, but they all have the fault pointed out by Downing, of taking on a "dingy green hue of foliage in winter," while the hemlock, white spruce, pinus pumilio, and other conifers will retain their characteristic colors in winter.