South Island Mosses Recently Found in the North Island.
[Issued separately, 30th September, 1931.]
Owing to the industry of South Island collectors in the past, its moss flora has been decidedly better known than that of the North, with the result that a number of species are recorded as being confined to the former region. Of late, however, a good deal of field work has been done in several districts of the North Island, and this has led to the discovery of several southern species. Unfortunately, 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. Generally speaking, bryological collections are not made except by those specially interested in the group. The consequent 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. So far as the rarer sorts are concerned, it suffices to mention that in the last few years, at least ten new or unreported species have been found in New Zealand, including representatives of genera, and even families, new to the country! In the subjoined list of South Island species found in the North Island, I have relied chiefly on Dixon's Studies in the Bryology of New Zealand for information as to the localities of the mosses in the south; whilst with regard to the North Island I have attempted, where the scanty knowledge at my disposal warrants it, to forecast what future research may show to be the comparative rarity of the species. A large or conspicuous plant is, of course, more easily established as “rare” than a small or insignificant one, and up to a point this is very true of the mosses, some of which are so handsome and striking as to catch the eye of a casual observer, whilst others are so insignificant as to escape the notice of an experienced bryologist. But it does not necessarily follow that because a moss is of striking appearance it will on that account be collected or noted by a student of the group. It may easily be passed over because of its superficial resemblance to some other species, and in this connection it must be remembered that very many mosses, even when in fruiting condition, cannot be identified without a microscopical examination. To put it bluntly, mosses often look very much alike, and the field-worker can never feel sure that he has noted or collected everything that even the most limited area has to offer. In order to facilitate the application of these considerations to the species in the list, I have given some particulars of size and appearance.
Dicranoloma grossialare (C. M.) Dixon.
South Island.—Mt. Arthur Plateau, T. F. Cheeseman. North Island.—Mt. Hauhungatahi, National Park, G.O.K.S.
This is fairly distinct for a Dicranoloma, but the genus, though of striking habit, is so well represented and the plants so abundant in higher altitudes that this species may have been overlooked. Nevertheless, the careful collecting of Mr R. Mundy at Ohakune, quite close to Mt. Hauhungatahi, has apparently not brought it to light; neither has it been found by me on other parts of Mt. Ruapehu. I sought for it recently on Mt. Arthur itself without success, and expect that it will prove to be very rare.
Seligeria Cardotii R. Br. ter.
South Island.—Fairly widely spread, according to R. Brown, but only on calcareous rock. I have found it on Mt. Arthur in a similar habitat. North Island.—Lake Waikaremoana, Hawke's Bay, alt. 2000ft; G.O.K.S.
On shaded limestone rock. A tiny plant, scarcely more than one-sixteenth of an inch high, including the seta. Such a minute species may well be comparatively common in its selected habitat, but no moss could more easily be overlooked.
Blindia tenuifolia (H.f. & W.) Mitt.
South Island.—Waimakariri Glacier; R. Brown. Stewart Island.—Mt. Thompson; R. Brown. North Island.—Mt. Ruapehu and Mt. Tongariro, National Park; G.O.K.S.
This is a montane moss that grows more or less submerged in glacial streams. In size and colour it is a striking plant, and the fact that it was only found twice by such an indefatigable collector as Brown, establishes it as a very rare species. I should think that the only possible extension of its northern distribution would be to Mt. Egmont.
Dicranella gracillima (C.M. & Beck.) Par.
South Island.—Dunedin; Otarama; Broken River. North Island.—Lake Waikaremoana, G.O.K.S.; Ohakune, R. Mundy; Atiamuri, K. W. Allison.
This is a very small terrestrial moss, and easily overlooked. It is probably fairly common in this Island.
Dicranoweisia antarctica (C.M.) Par.
South Island.—Widely spread on mountains. North Island.—Mt. Ruapehu (two localities); Rimutaka Hills, near Wellington, G.O.K.S.
Probably not uncommon in mountainous parts. In the field it strongly resembles robust forms of Weisia viridula (L.) Hedw., a very common moss, and could pass unnoticed accordingly.
Dicranum aucklandicum Dixon.
South Island.—Dunedin; Lake Te Anau; Kelly's Hill, West Coast Road. North Island.—Mt. Ruapehu, G.O.K.S. (two localities).
Another small terrestrial or rupestral species, and, of course, hard to find. It is impossible to form any opinion as to its distribution in this Island.
D. trichopodum Mitt.
South Island.—Otago, Hector and Buchanan; Paparoa Range, R. Helms; Clinton Valley, D. Petrie; Westland, T. W. N. Beckett; Mt. Arthur, G.O.K.S. North Island.—Ohakune, Mt. Ruapehu, R. Mundy.
In view of its fairly wide distribution in the South Island, I should expect it to be found here and there in the higher altitudes, but it is evidently rare. A fairly robust and quite noticeable moss, at any rate in fruit.
Mesotus celatus Mitt.
South Island.—Otago, Hector and Buchanan; Marlborough, J. H. McMahon; Mt. Arthur, G.O.K.S. North Island.—Mt. Hikurangi, 4500ft., G.O.K.S.
This moss, though a very rare fruiter, is conspicuous and distinct. It is remarkable that it has not been found on the central mountains of the North Island, and that Mt. Hikurangi, East Cape district, should be the only station for it at present.
Fissidens inclinabilis C.M.
South Island.—Christchurch and Dunedin. North Island.—Wairoa County, Hawke's Bay, E. A. Hodgson, G.O.K.S.; Atiamuri, K. W. Allison.
Like several of the New Zealand species of the genus, this is a very small terrestrial plant, and is probably not so rare as easily overlooked.
Didymodon Binsii (R. Br. ter.) Dixon.
South Island.—Port Lyttelton Hills, R. Brown. North Island.—Wairoa County, Hawke's Bay, E. A. Hodgson; G.O.K.S.
This is a small ground moss that grows in open places and is fairly conspicuous. It is not uncommon in the Wairoa district, but has apparently not been collected elsewhere, and is probably rare.
Tortula bealeyensis R. Br. ter.
South Island.—Fairly widely distributed. North Island.—Lake Waikaremoana, 2000ft., G.O.K.S.; Ohakune, 2000ft., R. Mundy.
This is a fine species, and is not likely to be overlooked by a collector, though it could be confused in the field with other robust members of the genus. An extension of its distribution in mountainous districts can reasonably be expected.
Physcomitridium Readeri (C.M.) Roth.
South Island.—Banks of River Avon, R. Brown. North Island.—Wairoa County, in drain, E. A. Hodgson.
An interesting little eleistocarpous moss which must be very rare.
Lepyrodon Lagurus (Hook) Mitt.
South Island.—Probably fairly widely distributed. North Island.—Mt. Ruapehu, R. Mundy; G.O.K.S.
A specimen in Colenso's Herbarium from an unlocalised finding is probably of his own collecting in Hawke's Bay district.
L. australis Hampe.
South Island.—Several stations. North Island.—Lake Waikaremoana, E. A. Sainsbury; Mt. Ruapehu, G.O.K.S.
Both the above species are well-marked corticolous plants, and are probably fairly well distributed in mountainous parts.
Entodon truncorum Mitt.
South Island.—Canterbury and Otago. North Island.—Lake Waikaremoana, G.O.K.S., E. A. Hodgson.
This is quite a conspicuous moss, but as it resembles Plagiothecium denticulatum in the field, it may have been passed over as that.
Pseudoleskea imbricata (H.f. & W.) Broth.
South Island.—Rare. North Island.—Mahia Peninsula, Hawke's Bay, on limestone rocks by sea; G.O.K.S.
Quite distinct in its terete branches and the close imbrication of the leaves when dry. I found it growing sparingly with Grimmia pulvinata, var., Barbula torquata, etc., on limestone boulders at the very edge of the sea, but not more than a few yards inland. Perhaps it will be found in other parts of the coast in a similar habitat. It could not be mistaken for any rupestral moss.
Sciaromium Bellii Broth.
South Island.—Otago, Southland, and Marlborough. North Island.—Patoka, Hawke's Bay, E. A. Hodgson.
This is a very rare water moss. The Patoka plant is also outstanding in that it is the only gathering in fruiting condition, there being a capsule present.