Art. XLIV. —On the Supposed Mount Bonpland Habitat of Celmisia lindsayi, Hook. f.
[Read before the Philosophical Institute of Canterbury, 6th September, 1905.]
Among several interesting species of plants discovered by Dr. W. Lauder Lindsay in the course of his visit to Otago in 1861–62 was the very fine Celmisia which now bears his name. This plant was especially notable since up till comparatively recent years it was supposed to be confined to that limited area of the south-east Otago coast where Lindsay had first collected it, although the genus is essentially alpine and subalpine. However, some years ago, Mr. Henry J. Matthews, whose important botanical explorations in the Otago lake district and elsewhere have added many valuable facts to New Zealand botany, brought from the Humboldt Mountains, of which Mount Bonpland is the principal peak, a Celmisia much resembling C. lindsayi. Also, the late Mr. W. Martin, of Fairfield, whose fine collection of alpine plants is well known, had collected in the same region a Celmisia, evidently most closely resembling C. lindsayi, which Mr. J. Buchanan published in 1888 under the name of Erigeron bonplandii,* that botanist having come to the conclusion that the suffruticose Celmisias should be united to Erigeron.†
That alpine plants frequently occur at sea-level is well known, while several species of Celmisia also occur in the lowlands. Such are Celmisia longifolia; C. petiolata, var. rigida,‡ of Stewart Island; C. verbascifolia, C. holosericea, C. vernicosa, of the Southern Islands; while quite recently Mr. A. H. Cockayne and also Mr. H. J. Matthews have collected C. coriacea near the sea in north-east Marlborough. Such cases are of considerable phytogeographical interest, which becomes greater where a plant is found only on the coast and in the alpine region but is wanting in the intermediate country.
In 1896 Mr. D. Petrie's most important “List of the Flowering Plants indigenous to Otago”§ appeared, in which the alpine habitat of Celmisia lindsayi is mentioned. “I have seen numerous living plants of this species brought by Mr. Henry Matthews, of Dunedin, from the neighbourhood of Lake Harris,”∥
[Footnote] *“On some New Native Plants” (Trans N.Z. Inst., vol. xix, 1887, p.213).
[Footnote] † “Description of a New Species of Erigeron” (Trans. N.Z. Inst., vol. xvii, 1885, p. 287).
[Footnote] ‡ This I consider a distinct species.
[Footnote] § Trans. N.Z. Inst., vol. xxviii, 1896, p. 540.
[Footnote] ∥ Lake Harris is in the close vicinity of the Humboldt Mountains.
writes Petrie. Mr. T. Kirk, however, commenting upon this statement, the next year writes, “the reputed Lake Harris station for this fine plant is very doubtful indeed, the plant being purely littoral.” Moreover, in the “Students' Flora” Kirk is still more emphatic, stating, “The reported habitats at Mount Bonpland and Lake Harris are erroneous.”* To understand Kirk's attitude in this matter one can merely make certain suggestions. He may have considered Matthews's plant as belonging to another species. But this is hardly probable, since Buchanan's Erigeron bonplandii, the plant of Martin's garden, and supposed to have been collected by the latter on the Humboldt Mountains, is referred by Kirk to C. lindsayi. It seems far more likely that Kirk considered some confusing of localities had taken place, especially as he himself had collected on the Lake Harris saddle and in that neighbourhood. Such a mistake with regard to a plant habitat is a most easy error to fall into when one is collecting largely from all parts of a region, and receiving plants in addition from other sources; and especially easy is it when one is collecting living plants rapidly and not labelling them as collected, but trusting merely to memory. Then, in sorting out, planting, and transplanting, there are additional chances of confusion. Be all this as it may, the above is Kirk's uncontradicted assertion, and until it is proved or disproved there must remain uncertainty as to the very important fact regarding the distribution of C. lindsayi.
But the receipt of certain botanical material from Mr. Mathews, together with two explanatory letters, has enabled me to throw some fresh light on the subject. Mr. Matthews thus writes: “In a day or two I will send you specimens of Celmisia lindsayi† from Nuggets and Celmisia sp. from Mount Bonpland…. The flowers certainly do not differ much, but I will ask your opinion on the foliage, &c., which to me appears entirely distinct. Kirk said, as you know, the Bonpland habitat was erroneous; and yet I saw acres of it, and brought some home a few months ago.” The italics are mine, and that statement entirely removes any suspicion as to “mixing of habitats.” There can consequently no longer be a doubt as to the existence of an alpine Celmisia closely allied to or identical with the coastal C. lindsayi.
The specimens arrived in due course, two living shoots in excellent condition, labelled respectively “Nuggets” and “Bonpland.” The following are some notes I made regarding the specimens:—
[Footnote] * “Students' Flora,” p.284.
[Footnote] † Nugget Point is the original habitat of C. lindsayi.
The two shoots bear a considerable resemblance to each other. Both have viscid, aromatic, rather soft leaves,* green on the upper surface and densely tomentose beneath. The tomentum—a very constant character in Celmisia species, and not sufficiently used for diagnostic purposes—is identical in both plants. It is smooth, very dense, closely adpressed to the leaf-surface, white and shining, and when magnified by 6 is seen to consist of fine cobwebby hairs. The midrib in both plants is prominent and large, especially towards its base, and pale-green in colour.† Some of the leaves are obscurely serrated. The leaves clasp the stem with a broad sheathing base which is stained purple on its lower half. The shoot-axes measure about the same in diameter in both specimens, 1·5 cm.; and the living leaves occupy the apical end of the shoot for about the same distance, while below are the withered leaves still attached to the stem.
There are, however, some differences, but these are merely of degree, and such as might be expected in any species from ordinary “fluctuating variation,” and especially in New Zealand plants, when we bear in mind the extraordinary plasticity of so many species with regard to changes in their environment. But examination of more material would probably lead to somewhat different results.
The Bonpland plant has smaller and slightly differently shaped leaves to the Nuggets plant. The leaf-veins are a little more prominent on the under surface of the leaf and rather more sunken on its upper surface, giving a somewhat more wrinkled character to the surface. The leaves are also perhaps rather stiffer and a little darker green. On the other hand, the Nuggets specimen is decidedly the more aromatic of the two.
The following are measurements of the leaves of the two specimens:—
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|cm. cm.||cm. cm.||cm. cm.||cm. cm.|
|11·7 by 2·2||2·6 by (?)||8·6 by 2·6||2·5 by 1·6|
|11·1 by 2·5||2·7 by 1·8||8·55 by 2·5||2·5 by (?)|
|11·4 by 2·5||2·6 by 1·6||8·3 by 2·6||2·45 by 1·7|
|11·2 by 2·55||2·8 by 2·55||9·9 by 2·8||2·4 by 1·7|
[Footnote] * Kirk describes the leaves as “coriaceous, but not thick”; but that description applies only to dried specimens.
[Footnote] † In the Handbook it is described as black, a character evidently taken from a dried specimen.
From the above it may be seen that the Nuggets plant has leaves longer considerably but narrower in proportion to the Bonpland plant, which consequently gives them a different shape.
An examination of the literature on the subject, of plants in my herbarium, and of notes which I took personally some years ago at Nugget Point, shows that the Nuggets plants vary considerably in dimensions of leaf. For instance, my notes taken on the 3rd October, 1902, give, as an average size of certain leaves measured, 10·5 cm. by 1·9 cm., and a specimen collected by me in the same locality some months later gives the following: 9·7cm. by 2·3 cm.; 10 cm. by 2·2 cm.; 8·4 cm. by 1·9 cm.; 9·8 cm. by 2·3 cm.; 7·5 cm. by 1·7 cm.; 7·2 cm. by 1·8 cm. A Catlin's River specimen collected by D. Petrie measures 14·6 cm. by 2·5 cm.; 11·2 cm. by 2·4 cm.; 14·5 cm. by 2·3 cm. A cultivated specimen sent by T. Kirk of the Nuggets plant measures 13·6 cm. by 1·7 cm.; 13·2 cm. by 1·9 cm; 12·9 cm. by 1·9 cm. Hooker gives the dimensions of Lindsay's specimens as 6·4 cm. by 1·25 cm., and the plate in Lindsay's paper* shows a comparatively small plant. But these figures on the whole confirm the statement above, that the coastal plant has longer but narrower leaves in proportion to their length than the Bonpland plant.
In my herbarium is also a flowering specimen of the alpine plant collected in Matthews's garden by Petrie. This, so far as the flower goes, exactly matches Nuggets specimens. Its leaves measure 9·3 cm. by 2·1 cm.; 9·8 cm. by 2·35 cm. The scape of the alpine plant is of the characteristic flexuous form, which Hooker called attention to as a peculiar characteristic of C. lindsayi. Petrie (l.c., p. 558) remarks that the Lake Harris specimens of Matthews “have a more robust habit than the sea-coast form.”
In order to further test the differences between the two plants, I cut a number of transverse sections of the leaves. These, though agreeing in the main as to palisade, spongy parenchyma, &c., show one difference—viz, that the Bonpland plant has invariably a two-layered epidermis, while the Nuggets plant has one of one layer only, though the latter is occasionally two-layered for a short distance. Thus, this anatomical distinction, again, is one rather of degree than of actual difference.
Such are the facts of the case with regard to the alpine and coastal plants. There is undoubtedly a Celmisia on the Humboldt Mountains, common also in many places, although Kirk, Petrie, and myself, who have all been in the vicinity of its habitat, have never collected it. Moreover, this alpine Bonpland form
[Footnote] * “Contributions to New Zealand Botany,” 1868.
differs from the coastal Nuggets form in some minor details, but only in such as might be expected from ordinary fluctuating variability, so that the two plants according to recognised floristic rules must be considered identical.
But are such floristic methods sufficient in this case? Mr. Matthews thus writes, and shows very clearly the position he takes with regard to the coastal and alpine forms: “In regard to Celmisia lindsayi and the Bonpland plant (sent yesterday), there is perhaps no clear actual botanical distinction, but when seen growing side by side they are dissimilar in many respects that could not be reduced to writing.” This statement of Matthews opens up a very wide and most important question, but here a few general remarks must suffice. Professor L. H. Baile thus writes: “Many of us feel that the present methods of nomenclature and description will be outgrown, for these methods are made for the herbarium and museum rather than for the field. It is a most suggestive commentary that the botanist may know the species when it is glued on an herbarium sheet, but may not know it when it is growing. The nurseryman or gardener may know it when growing, but not when it is in an herbarium. This is not merely because the botanist is unfamiliar with the field or the gardener with the herbarium. These men have a different fundamental conception of what a species is; they use different ‘mark’—one morphological, the other largely physiological. I believe that the gardener is nearer the truth.”* The fact is, such cases as the one under consideration, and dozens of others much more striking which could be selected from the New Zealand flora, cannot be settled by a mere morphological examination. The truth does not rest on the dictum or perhaps whim of one man, or indeed of a number of men, but upon the observation of a simple fact— the power of the particular form in question to reproduce itself “true,” or the contrary, from seed. If the progeny resembles the parent in those characters which distinguish this latter from all its allies, then we have to do with a distinct entity—an elementary species, as De Vries† has termed it—and such must receive a name; such elementary species are realities, whereas collective Linnæan species are merely ideas. The final court of appeal as to “specific value” is no longer the herbarium or study of the systematist, but the seed-bed of the experimental garden.
[Footnote] * “The Mutation Theory of Organic Evolution”: Six addresses given before the American Society of Naturalists at Philadelphia, 28th December, 1903. “Systematic Work and Evolution,” L.H. Baile (Repr. Science, n.s., vol. xxi, No. 536, 7th April, 1904, p. 12).
[Footnote] † H. de Vries, “Die Mutationstheorie,” band 1, chapter v, ·21, “Species, Subspecies, and Varieties,” pp. 115–20