The following Keys are intended to facilitate the student's endeavours to determine the names of New Zealand plants. I have tried to make them as simple as possible by avoiding the use of more technical terms than necessary, and by employing in many cases characters taken from the general habit of the plants. None of these Keys can, however, be used, without some previous study of the elements of structural botany; for the terms employed have each an exact meaning, which cannot safely be guessed at. The amount of study required depends much upon whether the student's powers of observation and of reasoning are good and accurate; but no amount of ability will obviate the absolute necessity of observing the characters of plants carefully and accurately, and clearly understanding the application of the terms used in defining these characters; and I would remind both teachers and students, that it is now a generally received opinion, that no subject is so well suited as systematic botany, to quicken the observing powers, and to improve the reasoning faculties of the young; and I believe that a little training in the use of these Keys alone, will sharpen the intellect of the quickest to a remarkable degree, and materially improve that of the dullest.