The following are the principal natural orders represented by the woody vegetation of this country, whether indigenous or introduced : -Berberidaceae, Tiliaceae, Rhamnaceae, Sapindaceae, Ilicineae, Caprifoliaceae, Cornaceae, Ericaceae, Ulmaeeae, Plata-naceae, Betulaceae, Cupuliferae, Salicineaa, and Coniferae. A few species are contributed by the Magnoliaceae, Cistineae, Tamaris-cineae, Simarubeae, Celastrineae, Hamamelideae, Thymelaceae, Elaeagnaceae, Lauraceae. and Juglandaceae. The orders here enumerated are composed almost exclusively of woody plants. The Rosaceae, Leguminosae, Oleaceae, Saxifrageae, and Araliaceae include nearly all the remaining species. Woody plants are described as Arborescent or Frutescent.

1. Arborescent

Arborescent. This division includes a vast number of subjects, varying almost indefinitely in minor details, such as size, habit, foliage, flowers, etc. Only those species which naturally form a single stem, instead of branching out at the base into a number of more or Less equal ramifications, come under this head. These may again be divided into Evergreen trees, distinguished by their persistent foliage; and Deciduous trees, those which shed their foliage in autumn, or only retain it in a withered or discoloured condition through the winter. Some trees, it should be observed, which are evergreen in their native countries, become deciduous when transferred to a colder climate, and the reverse is said to apply to some of our indigenous species when taken to a warmer climate. But the distinction is clear enough for all practical purposes. As generally understood, the term Evergreen is restricted to those plants whose foliage is persistent, and retains its natural hue during the whole of the year, or during several years. Or perhaps a better definition would be that the old leaves persist and retain their beauty until after the succeeding growth has furnished a fresh supply of fully developed foliage. Some of these, it is true, assume a different tint in winter, but the same leaves regain their freshness with the advent of spring.