The whole coast of the Mexican Gulf, from the Pearl River eastward, through Alabama and a great part of Florida, is occupied by the so-called "pine barrens," which extend far into the interior. These "vast monotonous tracts of sand, covered with forests of gigantic pine trees," are not less a characteristic feature of North America than the "rolling prairies." They are not limited to this part of the United States, but occur to a great extent in Virginia, North Carolina, and elsewhere. Tennessee and Kentucky, though the plough has passed over extensive areas, still possess large forests, and the Ohio flows for hundreds of miles among patriarchal trees, with a rich undergrowth of azaleas, rhododendrons, and other beautiful shrubs, bound together in chains of flowers by creeping plants. When America was discovered, one mass of unbroken forest spread over the mainland, from the Gulf of St. Lawrence and the Canadian Lakes to the Gulf of Mexico, and from the Atlantic Ocean it crossed the Alleghany Mountains, and spread in gloom and grandeur over the valley of the Mississippi--an ocean of vegetation swelling and sinking for upwards of one million of square miles. "Then all the broad and boundless mainland lay, Cooled by the interminable wood, that frowned O'er mound and vale, where never summer ray Glanced, till the strong tornado broke his way Through the gray giants of the sylvan wild; Yet many a sheltered glade, with blossoms gay, Beneath the showery sky and sunshine mild, Within the shaggy arms of that dark forest smiled."[91]