Art. LIV.—Two New Ferns..
[Read before the Wellington Philosophical Society, 5th April, 1905.]
In December, 1903, one of my sons, who had been visiting Auckland, brought me some plants of ferns which are either wanting or extremely rare in this part of the colony, and I potted them at once. Among them was one which appeared strange to me, and which my son said he had found in some scrub near Takapuna Lake. It was a male plant with only barren fronds about 2 in. long, and which looked like those
of young Lomaria filiformis, but seemed too thick and harsh to be so. It was also a tufted plant, having a crown of about a dozen fronds, without any sign of the creeping roots which are characteristic of L. filiformis. The plant grew well, but it was not till near the end of the following year that it began to produce fertile fronds, which were rose-coloured when young. This is so common with Lomaria lanceolata, particularly when growing on limestone soil, that I thought the plant might be a peculiar northern form of that fern. As the new fronds developed I saw that the plant was a Doodia, though different from either D. media or D. caudata, both of which I have had growing for many years. It has more of the peculiar tailed pinnæ of D. caudata, and differs from D. media in many respects. I have had plants of D. media, not only from the neighbourhood of Wanganui, but from Wellington, Nelson, and Auckland, and they were precisely similar in every case. There were never more than three or at most four fronds on a crown, and these were lanceolate. In fact, I never could see any difference between D. Media and the Australian D. aspera, except that the former was a much larger plant, and had rather fewer fronds. The new Auckland plant has no less than twenty-one fronds, and these, instead of being lanceolate, have their pinnæ of nearly equal length throughout, and these shorten and taper rapidly towards the apex of the frond. The pinnæ are also far shorter and more obtusely pointed than those of D. media. Thus, though approximating to the latter, the fern is of a far more handsome and compact habit—so much so that I think it worthy of being separately classed, and would suggest Doodia aucklandica as a fit name for it.
In July, 1903, I received a parcel of ferns from Waikanae They had been taken up with lumps of earth in which they grew, but as they had been several days out of the ground, and reached me late in the day, I potted them without much examination. There were several plants of Botrychium ternatum, variety cicutarium, and what appeared to be a cluster of Botrychia growing close together. The plant grew well, but I paid no particular attention to it till I put it in as one of a collection of ferns exhibited at our spring horticultural show on the 30th November. During the show the Rev. Z. Spencer, who has collected ferns for very many years, and has the best collection of pressed specimens of any one in Wanganui, remarked that I seemed to have wrongly labelled the plant, and that it seemed to him to be a Pteris, though one which he did not know. This caused me to observe the plant more carefully, and I found that he was right. The plant is clearly a Pteris, but differs materially from either of those yet classified
as belonging to the colony. It approximates to P. tremula, but has important differences. P. tremula has not more than six or eight fronds forming the crown, and these have very long stalks, are broadly triangular or rhomboidal in form, and are of a light-yellowish-green colour. The new plant has now twenty-one fronds in its crown, and these are so narrowly rhomboidal as to appear almost lanceolate, while the stalks are quite short. The colour is a dark almost olive green, and the strong aromatic scent which belongs to P. tremula, and which is so powerful as to be actually unpleasant in hot weather, is entirely wanting. Again, the ultimate divisions of P. tremula grow touching each other, are ½ in. or more long by about 1/10 in. wide at the bases, which are completely sessile, and from which the divisions taper gradually to sharp points, the fructification extending along the whole length of both sides. In the new plant these ultimate divisions are much further apart, and so narrowly sessile as to be almost stalked. Above this apparent stalk they widen suddenly for ¼ in. or more, and then become ovate or very bluntly pointed. In many instances they are cut into shallow lobes, and in such cases the fructification is confined to the outer portion of the lobes. But perhaps the greatest distinction is in the habit of the plant's growth. P. tremula has an erect habit, the crown gradually rising till in old plants it becomes a caudex 1 ft. or more in height. The new plant, on the other hand, spreads horizontally by the production of lateral fronds, so that even now it is rapidly filling a pot 5 in. in diameter. Altogether, though approximating, as I have said, to P. tremula, it is very different in appearance, and far more compact and handsome than that fern; and I think the differences are such as to make it worthy of being separately classed. The late Mr. Travers had a house at Paraparaumu, and I thought this fern might have grown from spores of some kind which he had in cultivation; but I cannot learn that he had such a plant, and there is none mentioned in the “Synopsis Filicum” which seems to agree with it. I think, therefore, that it may be provisionally named Pteris novœ-zelandiœ. It may be observed that in both the above cases the plants approximate to some already classified, but that they are such an improvement on those others, particularly in their habit of growth, as to seem to deserve separate classification. Though there is great variation in some of our New Zealand ferns, yet in every case the changes seem to have been evolved gradually, as there are connecting-links between the different forms which are difficult to assign to either. In both the cases, however, which I have mentioned the change is more than that of mere form—it is of habit of
growth; and, if a change, has apparently been evolved suddenly. The Doodia, for instance, is so totally different from the ordinary D. media, even as found at Auckland, that no one only partially acquainted with our New Zealand ferns would for an instant regard the two as merely different forms of the same plant.
I observe that in a paper published in the last volume of Transactions Mr. A. Hamilton quotes a remark which I made in 1882 as to the apparent paucity of cresting in our New Zealand ferns, a view in which the late Professor Kirk and Mr. H. F. Logan concurred with me. Since that date I have met with sundry examples of crested ferns, and have at present such forms of Adiantum formosum, Hypolepis distans, and Pteris tremula. In my book on our ferns a very remarkable dwarf form of Polypodium pennigerum, which was a mere mass of cresting, is figured on pl. xxv. It seems to me that cresting arises from plants growing under some particularly favourable conditions, as in several cases my plants have become so under cultivation. I notice that when a plant thus breaks away from the normal type, seedlings from it are apt to exhibit the peculiarity in even an exaggerated form, and I think that the great variety of appearance in the English ferns has arisen from persons having taken up and cultivated plants which presented any peculiarity. Before I became blind I had more than twenty quite distinct forms of the English lady fern, and about fifteen of the male fern, as well as hart's-tongue fern, which was a mere mass of cresting. Even now I have a form of lady fern in which the pinnæ are depauperated into mere semicircular projections from the midrib, and then have a heavy tassel of cresting at the end of the latter. Anything more different from the ordinary type of the lady fern it would be hardly possible to conceive. Mr. Hamilton's peculiar examples seem to have been mostly of one kind of fern, Lomaria fluviatilis, and to have been found in one specially favourable locality—which agrees with what I have above stated as to these peculiarities being worked under particular conditions. I was very glad to see that he was drawing attention to these variations, as they are very interesting to lovers of our ferns, and should be reported when observed. I think it is a great pity that more people do not cultivate our ferns, as many of the rarer and more delicate ones bid fair to become extinct as the country is cloared and brought under cultivation. It is very interesting to grow ferns from the spores, and it seems to me that this will be the only means of preserving some kinds.