Nat. Ord. (Natural Order) Conifer�. Lin. Syst. (Linnean System) Mon�cia, Monadelphia. THE Pines compose by far the most important genus of evergreen trees. In either continent they form the densest and most extensive forests known, and their wood in civil and naval architecture, and for various other purposes, is more generally used than any other. In the United States and the Canadas, there are ten species; in the territory west of the Mississippi to the Pacific, including Mexico, there are fourteen; in Europe fourteen; in Asia, eight, and in Africa, two species. All the colder parts of the old world �the mountains of Switzerland and the Alps, the shores of the Baltic, vast tracts in Norway, Sweden, Germany, Poland, and Russia, as well as millions of acres in our own country, abound with immense and interminable forests of Pine. Capable of enduring extreme cold, growing on thin soils, and flourishing in an atmosphere, the mean temperature of which is not greater than 37� or 38� Fahrenheit, they are found as far north as latitude 68� in Lapland; while on mountains they grow at a greater elevation than any other arborescent plant. On Mount Blanc, the Pines grow within 2,800 feet of the line of perpetual snow* (* Edinburgh Phil. Journ.). In Mexico, also, Humboldt found them higher than any other tree; and Lieut. Glennie describes them as growing in thick forests on the mountain of Popocatapetl, as high as 12, 693 feet, beyond which altitude vegetation ceases entirely.** (** Proc. Geological Soc. Lond. Arb. Brit.)
