It was in Texas, and in the rocky, arid, and hilly plains, that the French botanist Trécul discovered several notable varieties of Yuccas, to one of which, a new, and certainly the most beautiful species, his name has very justly been affixed: the _Yucca Tréculeana_. It raises its tall panicle of gorgeous flowers from the centre of a crown of glossy, rigid, spear-like leaves, like a victorious trophy. In Eastern Texas we note the first appearance, in the drier and stonier portions of the Prairies, of a representation of the family _Cactaceæ_, the _Opuntia frutescens_, frequently growing side by side with the _Silphium terebinthinaceum_. The _Opuntia_ is more generally known as the "Indian Fig" or "Prickly Pear," from the large purple juicy fruits which it yields. The _Silphium_ belongs to the family of _Compositæ_. But Western Texas is the true birth-place of these oleaginous plants, some of which, such as the _Echinocactus robusta_, the _Mamillaria rodantha_, and the _Opuntia microdasys_ ("small-thorny Opuntia"), are cultivated in our apartments, where they require but very little attention. M. Trécul has discovered in this region a new and rare variety of Echinocactus (_E. Tréculeanus_), some kinds of Cereus, and, especially, the _Cereus Peruvianus_, a beautiful plant with large showy flowers. Such are the principal plants which, in North America, characterize the vegetation of the Prairies and the Savannahs. This rapid and condensed description will show the reader that the species most extensively spread belong to the genera in which are grouped the more common inhabitants of our own Old World meadows and grassy plains. * * * * * If we now transport ourselves, on the poet's winged Pegasus, that takes no account of distance or of natural obstacles, to the Equatorial zone of the New World--into Guatemala, for example--we shall find the undulating and verdurous prairies giving place to high table-lands furrowed by deep and romantic ravines. Their botanical interest, however, is trivial, and their vegetation of a meagre and stunted kind. But between Guatemala, Nicaragua, and Honduras, lies an extensive valley, locally named _Llanora_, sown with numerous beautiful varieties of plants. Among them the _Gramineæ_ family predominates, and, without attaining the proportions and the quality of the herbs which we shall meet with in the interior, form breadths of meadow very charming in their rare fresh greenness. From the summit of the Cordilleras, in the neighbourhood of Bogota, at an altitude of about 3200 feet, the eye surveys almost the entire extent of those vast level plains which stretch from the base of the mountain-chain to remote Brazil, Guiana, and Venezuela.