many obligations to Professor E. Hackel, of Graz, Austria, for undertaking a critical examination of the whole of the New Zealand grasses, and for furnishing me with a series of very full and complete notes, with permission to use the same for the purposes of this work.
The elimination of the naturalised species from the present work, although absolutely necessary to keep it within the limits of a single volume, will not be altogether satisfactory to the student. A beginner cannot be expected to distinguish between the indigenous and introduced species, especially when it is remembered that in several districts the latter now constitute the larger portion of the flora, and that there is no part of the country, however remote, into which some plants of foreign origin have not penetrated. Altogether, over six hundred species, or nearly one-half the number of the indigenous flowering-plants, have succeeded in establishing themselves. I am not without hopes that I may be enabled to prepare a supplementary volume containing concise but sufficient descriptions of the foreign element of the flora; for this alone will remove the inconvenience resulting from the want of a ready means of determining all the plants which a student may observe in any district. In the meantime, I have given in the Appendix a nominal list of all well-established naturalised plants, with references to books in which descriptions of them can be found. As most of the species are of European origin, I would recommend the student to provide himself with a copy of Hooker's "Students' Flora of the British Islands," or some similar work, and to use it in conjunction with this publication.
It is not to be expected that a work containing descriptions of over 1,550 species of plants can be prepared without the occurrence of errors and imperfections, and for these I must ask the indulgence of the reader. One serious disadvantage under which I have laboured, and which I share in common with all colonial botanists, is the impossibility of examining those European herbaria in which the types of so many of the published species are deposited; and consequently mistakes may have been made in the identification of the species, especially in genera like Veronica, Gentiana, Myosotis, &c. But I trust that the number of such errors is not large. Their detection may be safely left to future workers.
A few statistics respecting the extent and composition of the flora may be of interest. The total number of species described, including a few additions given in the Appendix, is 1,571, of which 1,415 are
