[Read before the Otago Branch, October, 1945; Received by the Editor, January 9, 1946; issued separately, September, 1946.]

This paper contains a catalogue of the mosses known to be indigenous to the mainland of New Zealand and the off-shore islands, but excludes those of the Kermadecs, Chathams, and Subantarctic Islands which are not known to occur on the mainland as well. It likewise gives an account of the known distribution of each both within New Zealand and abroad. The need for such an investigation is evident from Sainsbury's observation (Trans. N.Z. Inst., vol. 62, p. 82) in 1931: “Our knowledge of the distribution of the mosses in this country is so slight that the finder of a new station for a species has practically no data on which to decide whether he is confronted with a case of discontinuous distribution, more or less extreme, or whether there is a chain of intermediate stations linking up his find with the nearest known locality … the paucity of field-workers and the outstanding difficulty of their task make it impossible for them to form any but provisional views on the distribution of even the most common species.”

The comparative scarcity of bryologists and collectors and of reliable records, combined with the fact that large tracts have been investigated, either not at all or at best most superficially, even to-day makes a complete picture of moss distribution impossible. In this regard it is well to recall Sir J. D. Hooker's remark in his Introductory Essay to the Flora Novae-Zelandiae (p. vi) that, “It takes a practised eye and some previous knowledge thoroughly to explore a small district rich in Mosses and Hepaticae.” Nevertheless, a study of the following tables will reveal that more than a good beginning has been made, and the general pattern of the ultimate picture has already begun to take shape.

The first account of New Zealand's bryophytic flora was presented by Sir J. D. Hooker in Volume 2 of his monumental Flora Novae-Zelandiae, published in 1855. This was followed twelve years later by his Handbook of the New Zealand Flora, part II of which enumerated some 362 mosses, of which 325 were recorded as growing on the mainland. Of these, 296 are still recognised as valid species, though in numerous cases under a revised nomenclature. Prior to these two publications Sir W. J. Hooker had in 1820 published his Musci Exotici; but all New Zealand mosses there recorded, described, and illustrated had come from the single area of Dusky Sound in Western Otago, where they had been collected in 1791 by Dr. A. Menzies. Sir J. D. Hooker's collecting was mainly confined to the Bay of Islands area.

Pioneer research into the bryophytic flora was also conducted by Dr. Lyall, surgeon to the survey ship Acheron, between the years 1847 to 1851; and in 1876–7 by Dr. Sven Berggren, a Swedish botanist of note, whose moss collections exceeded 3000. In 1861–2, Dr. W. Lauder Lindsay, the Scottish cryptogamist, while on a health trip to New Zealand, spent several months studying the cryptogamic flora of Eastern Otago. His major results were published six years later in Contributions to New Zealand Botany, wherein are listed 44 mosses from the Dunedin area.

New Zealand students of the moss flora, active in the latter half of the century, include W. Colenso, J. B. Armstrong, J. Buchanan, T. Kirk, W. Bell, R. Brown, T. Naylor-Beckett, D. Petrie, and others, who either published their results in the Trans. N.Z. Institute or forwarded their material to W. Mitten, V. F. Brotherus, Carl Müller, C. Warnstorf, or other authority. The combined results of their labours were subsequently collated by H. N. Dixon, and, after critical review, were published by the New Zealand Institute in a series of six bulletins entitled Studies in the Bryology of New Zealand. Herein were enumerated some 469 species under a modernised nomenclature.

During the present century bryological research has been continued by D. Petrie, W. Gray, L. Cockayne, K. W. Allison, Mrs. E. A. Hodgson, Miss L. B. Moore, F. B. Matthews, V. Zotov, R. Mundy, G. O. K. Sainsbury, the writer, and others; and their combined labours have thrown quite a flood of light on problems of distribution. Most of the material collected by the above workers has passed through the hands of H. N. Dixon, of England, or of G. O. K. Sainsbury, of Wairoa, or of both, which gives additional assurance that the records are based on correctly identified material.

Since Dixon's review of the moss flora, completed in 1928, numerous papers have been published which have added considerably to the catalogue of indigenous mosses, and it may be expected that the ultimate list will not fall far short of 600, as predicted by J. D. Hooker a century ago. The total species listed by Dixon in the Studies was 469; the present list enumerates 493 species and 51 recognised varieties, to which must be added the numerous species and varieties of Sphagnum, a genus omitted from the present statistical review on account of the uncertainty attending the identification of many New Zealand species. The estimated total inclusive of the Sphagnaceae now stands at 513 species and 54 named varieties, or a grand total of 567.