[Read before the Otago Branch, October 17, 1950; received by the Editor, October 25, 1950]

No previous attempt has been made to compile a catalogue of the Mosses indigenous to the Dunedin Botanical Subdistrict; but any previous list would have been premature, as recent investigations by Allison, Simpson, Thomson, and the writer have greatly supplemented those previously known from the area.

This sub-district has been delimited by Simpson and Thomson (Trans. Roy. Soc. N.Z., 67, 431–432); but it may be regarded as all that area inland from the coast between Akatore and Stony Creek, just south of the Shag River, to a line extending from Waitahuna Hill, in the south, through Hindon and Scratchback Hill to the coast at Stony Creek. This block of country has an approximate area of 145,000 hectares, or 560 square miles. It may be well to note, however, that there is no evidence that the mosses are in any way restricted in their distribution to the same botanical districts as have been defined for the flowering plants.

The earliest collections were made by William Martin, grandparent of the writer (1850–1), and by Sir James Hector and John Buchanan, a number being recorded by Hooker in his Handbook of the New Zealand Flora. These were supplemented later by Dr. Sven Berggren, Dr. Lauder Lindsay, Mr. Donald Petrie, and Mr. William Bell. Of some 3,000 moss collections throughout New Zealand made by Berggren in 1873–5, 42 were obtained in Dunedin or at Evansdale. These were determined in 1937 by Dixon and Bartram, and a representative portion is now housed in the Auckland Museum. Lauder Lindsay, while a guest of William Martin in 1861, collected mosses in and south of Dunedin as far as the Clutha River. A list of his gatherings is contained in “Contributions to New Zealand Botany,” published in 1868.

The last decade of the century found Mr. William Bell, of Pine Hill, and Mr. D. Petrie, chief inspector of schools for Otago, actively engaged in collecting the local bryophytes. Though each was the discoverer of many species new to New Zealand—several from this sub-district—neither at any time published anything concerning the mosses, being content to send copious suites of specimens to such authorities as Brotherus, Mitten and Dixon. Bell's herbarium cannot now be traced, but Petrie's moss collections are now housed in the Dominion Museum herbarium.

Nothing further was done in investigating the local mosses till the fourth decade of the present century, when Simpson and Thomson, in the course of a detailed study of the plants of the Dunedin district, made numerous collections of the mosses, which are now housed in the herbarium of the Plant Research Bureau at Wellington.

They record some thirty-five of the local epiphytic mosses in their paper on the flora of the Dunedin Botanical Sub-district of the South Otago District (Trans. Roy. Soc. N.Z., 67, 438).

More recently K. W. Allison, chief local officer of the Forestry Department, has collected the bryophytes of this area, and has been successful in locating a large number of species not previously noted by other collectors, or species not locally observed in recent years. Some of these he recorded in a paper (Trans. Roy. Soc. N.Z., 77, 278–283), since when he has collected many others. Most of these recently found have been made available to me for inclusion in this paper. The writer has also collected a majority of the local mosses, including several not noted by others. All are represented in the herbaria of the Auckland Museum (Berggren's), Dominion Museum (Petrie's). Plant Research Bureau (Simpson and Thomson's), or in the private herbaria of Allison, and the writer. The total at present known is 285, or half the total moss flora of New Zealand.

Further additions are to be expected, but their number is unlikely to be large, and the time seems opportune to record those already collected or observed. The rapid disappearance of the forest cover, and the changes consequent on settlement, cultivation, drainage, burning, and grazing are making the extinction of many local species almost a certainty within the area.

Every botanical district is bounded by an ecotone of varying width, so that it is not possible to delimit the area by a line. For this reason a number of species are included which are technically located outside the boundary set by Simpson and Thomson. Such are records from Akatore, Waihola, Horse Range Road, etc.

A number of mosses collected in the Dunedin Sub-district by Berggren in 1874 have not subsequently been found in the Dunedin area. Such are Campylopus holomitrium, Oligotrichum tenuirostre, Rhacopilum robustum, Thamnium latifolium var. elongatum and Thuidium denticulosum. The same thing applies to Breutelia elongata gathered by Hector and Buchanan in Waipori Gorge and recorded by Hooker; but the finding this year of Psilopilum bellii by Allison after a lapse of 60 years, indicates that the others may yet be re-discovered in the area.