The following Keys are designed to facilitate the reference of any plant to its proper Order; and it is hoped that the one may so supplement the other that in most cases little difficulty will be found. A synopsis is likewise given of the genera under each order, and of the species in most of the larger and more difficult genera. All the more important synonymy is cited, including references to the principal figures. The geographical range is indicated as nearly as our present knowledge permits, but the habitats of many of the rare or local species will doubtless be much extended as the State is more thoroughly explored. Additional species will also be discovered, and the descriptions of the known species here given may prove in some cases to be defective or erroneous. In formation in regard to any additions or corrections is solicited for an appendix to the second volume, or for a future supplement.