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19. XVIII. Eucalyptus Muelleriana, Howitt.

   
Variation in this and other Stringybarks  219 
Affinities (E. Wilkinsoniana, R. T. Baker, and E. nigra, R. T. Baker, are here considered)  220 




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Description.

E. Muelleriana, Howitt.

(For Description, Synonomy, Range, &c., see Part I, as E. pilularis, var. Muelleriana.)

IN dealing with the Stringybarks, I have been vainly looking for characters which will differentiate all forms. For example, I have endeavoured to separate them by the seedling or juvenile leaves (width, and the presence or absence of stellate hairs). But I find that these characters, like all others in Eucalypts, vary. The state of ripeness of the fruits counts for much, the state of being capitate counts for little in classification. The juvenile leaves of Stringybarks (viz., E. capitellata, macrorrhyncha, eugenioides, Muelleriana) appear to be beset with hairs, more or less,—Muelleriana, perhaps, least of all. Those of E. eugenioides are usually narrowest. Those of E. capitellata and E. macrorrhyncha are broader, though the latter are usually narrower than the former. Those of E. Muelleriana vary much in width, and are sometimes very narrow. “The extremely shiny upper surface” of the leaves of this species (Howitt) characteristic of the type, unfortunately for purposes of classification, breaks down in some of its forms.

An instructive series of specimens was collected by Mr. A. W. Howitt,— (a) Armidale, New South Wales, with narrow juvenile foliage; (b) between Chandler and Styx Rivers: “Up to 50 feet, bark stringy to smaller limbs and branches.” This has juvenile foliage of intermediate width. (c) Styx River and Armidale: “A Stringybark tree, tall, up to 60 or 70 feet.” The opposed juvenile leaves up to one inch and a half wide; (a), (b), (c) belong to the same species; the transition between them is evident.

I have received from Mr. A. W. Howitt seedlings and other juvenile foliage of his typical E. Muelleriana, from Long Cutting, Tambo River, Victoria. The seedling leaves are half an inch in diameter, while the juvenile leaves, still in the opposite stage, are an inch and a quarter broad, with the stellate hairs so common in the Stringybarks. I cannot point out any differences between these juvenile leaves and those of the New South Wales (a), (b), (c) just referred to. The leaves of (a) are as narrow as those of E. eugenioides, while those of (c) are broader than those of E. Muelleriana were formerly supposed to be. Examining them from all points, I am of opinion that different botanists may look upon them as belonging to E. eugenioides, or to a small-fruited form of E. Muelleriana.

E. Muelleriana appears to have a number of associated forms closely related to it, and, for that and other reasons, I think it is better to look upon it as a species, and not as a variety. I, therefore, modify my views as to the rank of E. Muelleriana, as expressed in Part I of this work.




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The fruits of typical E. Muelleriana are, on the average, about half an inch in diameter. It might be desirable to give the small-fruited forms (i.e., those about a quarter of an inch in diameter, or rather more) a name, for it is they which show transit to and are confused with E. eugenioides. It might be desirable to renew the variety name minor which was applied to forms of E. lœvopinea by Mr. Baker, but, as regards myself, I must say that I am unable to define the small-fruited forms as distinct from E. eugenioides. They are simply portions of a curve.

E. Muelleriana is known as “Yellow Stringybark,” from the yellowness of the inner bark, which yellowness also often exhibits itself as a stain more or less marked throughout the wood. At one time I hoped that this yellowness (where evidence of its presence is available) might be a useful diagnostic character. It is certainly useful sometimes, but it breaks down in that it is observable in E. eugenioides and other species. The presence of this colouring matter in various trees is worthy of investigation by the chemist, as it may be of some aid to diagnosis not clearly understood at present. I have spoken of the yellow colour being present in species other than Muelleriana; I now give an instance of its absence from Muelleriana. “Pale Stringybark,” Mt. Lofty, S.A. (R. H. Cambage, 20th March, 1901); also, same locality (Walter Gill, Nov., 1901). Mr. Gill adds the note “The inner bark has none of the bright yellow colour of the Wingello, New South Wales, trees you and I felled in March.” The Wingello trees are typical Muelleriana. See Part I, p. 40.

The Mt. Lofty specimens have duller buds and fruits, shape of fruits some-what pear-shaped, rim well defined, reddish-brown, slightly domed, tips of valves slightly exsert. The fruits are reminiscent of those of some South Australian specimens of E. diversifolia, Bonpl.

Affinities.

1. E. pilularis, Sm.

Its affinity to E. pilularis, Sm., I have abundantly made clear in Part I of this work. I sometimes cannot separate them on herbarium specimens. E. semicorticata, F.v.M., Brisbane River (received by me from Kew), has the pointed buds of E. pilularis, and the fruits of E. Muelleriana. I can only repeat that E. Muelleriana cannot be separated by hard lines from E. pilularis.

2. E. eugenioides, Sieb.

I do not know on what character—juvenile foliage, mature foliage, buds, fruits, bark, timber, E. Muelleriana (in its small-fruited forms) can be absolutely separated from E. eugenioides, Sieb. I have already touched on this point, both under E. eugenioides and in my preliminary remarks under E. Muelleriana. That being so, I cannot find fault with a botanist who does not see eye to eye with me in


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regard to the placing of this and that intermediate specimen in one species or the other. This is inconvenient, but the convenience of taxonomists has to give way to the grand law of variation.

I look upon E. Wilkinsoniana, R. T. Baker, and E. nigra, R. T. Baker, as being inseparable from E. eugenioides on the one hand and from E. Muelleriana on the other,note and I have made careful investigations in the forest.

E. Wilkinsoniana, R. T. Baker, Proc. Linn. Soc. N.S.W., xxv, 678 (1900). Syn. according to Mr. Baker. E. hæmastoma,note Sm. var. (Mueller in Eucalyptographia Dec. 2); E. lævopinea, var. minor, Baker.

The affinity of E. Wilkinsoniana with E. Muelleriana is an inference already made by Mr. Baker, partly on oil determination, but made by me on morphological grounds. Mr. Baker's original view was that this tree is a small-fruited form of E. Muelleriana (his lævopinea) and I think that that view has much to support it. It, however, ignores the obvious relation to E. eugenioides.

The type of E. Wilkinsoniana came from Marulan, also Barber's Creek (H. J. Rumsey). Specimens were sent to me also from the Glenrock paddocks, Barber's Creek, by H. J. Rumsey. Type specimens also from Sutton Forest (R. T. Baker). All these localities are very familiar to me, and the tree was collected by me long before it was described. Specimens from Burragorang (R. T. Cambage) and many other localities also match the type.

The fruits vary a good deal. See the remarkable differences of the forms of two heads of fruits from the same branch at Barber's Creek (H. J. Rumsey, the original collector of the type specimens). See fig. 17, pl. 38.

Mr. Baker's statement in his description of E. Wilkinsoniana that E. lævopinea never has a red rim appears to be founded on a misapprehension.

An extreme form of the fruits (from Sutton Forest) is that shown in the figure of E. Wilkinsoniana (Pl. 38, fig. 18). I have precisely the same form from 1 mile south-west of Parramatta, Wianamatta Shale formation (R. H. Cambage). Sometimes (e.g., same place and collector) the fruits are more constricted at the orifice, showing transit to E. pilularis. This shape of fruit is common enough in typical Muelleriana, whose fruits are, however, larger. Following is the same form.

E. pilularis, Sm., Gladesville, Sydney (H. Deane, May, 1886; J. L. Boorman, Dec., 1898) normal apparently in every other respect except that the size and shape of the fruits very closely approximate that of E. Wilkinsoniana figured at pl. 38, fig. 18.

The fruits of E. lævopinea, R. T. Baker, from Gulf Road, Rylstone (R. T. Baker) display such variation in size and shape as to have caused differences of views as to the species. For example, in Proc. Linn. Soc. N.S.W., 1896, 803,


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and 813, Mr. Deane and I referred some of them to an abnormal form of E. macrorrhyncha, between it and capitellata. That they are identical with E. Muelleriana, Howitt, has since been shown, but I would point out the resemblance in shape to those of some fruits of E. Wilkinsoniana.

The white-dotted appearance of the fruits common in E. Muelleriana is common on those of other Stringybarks, e.g., E. eugenioides and E. Wilkinsoniana and E. nigra.

The granular or roughened appearance of the rim which is specially common in E. Muelleriana is seen also in E. Wilkinsoniana, E. macrorrhyncha (e.g., Barber's Creek), and other forms.

The pale-coloured shiny buds of E. Muelleriana are seen also in E. Wilkinsoniana.

The depressed hemispherical fruit seen in E. Wilkinsoniana is common in northern E. Muelleriana and E. eugenioides.

Many other specimens (some are figured, e.g., 17 and 18, pl. 38) could be cited, showing that E. Wilkinsoniana cannot be considered a species apart from E. Muelleriana.

Let us now consider E. nigra, R. T. Baker, Proc. Linn. Soc. N.S.W., xxv, 689 (1900).

The type specimens of E. nigra, R. T. Baker, have usually thin rims to the fruit, and the tips of the valves barely protrude. They appear to be precisely matched by Kanimbla Valley (A. H. S. Lucas, March, 1900; J.H.M., February, 1901), a typical Stringybark (with yellow inner bark), and from the same tree I collected the broad-rimmed fruits of E. Muelleriana (see fig. 14, pl. 38). In other words, the fruits of E. nigra are not always thin-rimmed, varying, in this respect, in the same tree.

The leaves, buds, flowers, and fruits show that E. nigra cannot be separated from those of E. Muelleriana, although I have made earnest endeavours, extending over a long period, to separate them. The type-specimens come from Ballina, Richmond River, and Canterbury, Sydney.

E. nigra is, in my view, one of the forms which form part of the series between E. eugenioides and E. Muelleriana, and we have here but another instance of the protean forms of the Stringybarks.

I believe that Mr. Baker's E. nigra even extends to Victoria, and that the specimen, Upper Yarra, October, 1889 (C. Walter), looked upon by me as a remarkable form showing transit between E. regnans, F.v.M., and E. vitrea, R. T. Baker (see Part VII, fig. 5, pl. 34), may be looked upon as a form of


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E. Muelleriana (or of E. eugenioides, Sieb., as Messrs. Luehmann and Walter imagined it to be). In Eucalypts which are aberrant (and this remark applies more or less to other genera) it is often the case that they may be referred to more than one species, according to the point of view.note

As to the reputed inferior quality of the timber of E. nigra as compared with E. eugenioides, I have some timber of the former which seems as good as any of the latter; indeed, I cannot tell any difference between the two. I would suggest that the reputed inferiority of E. nigra timber is owing to local causes.

In northern New South Wales (e.g., “Stringybark,” Acacia Creek, Macpherson Range, W. Dunn (No. 72), and “Woolly-butt,” Armidale district, H. A. Perrott) we have Stringybarks with broader juvenile leaves than those of typical Muelleriana, the fruit smaller, and sometimes a little angled. The juvenile leaves appear to be quite identical with specimens from Eden, in the extreme southeast of New South Wales, collected by Howitt, and referred to E. eugenioides.

The tree also occurs in southern Queensland, e.g., Stanthorpe (A. Murphy), “the common Stringybark of the district, runs out near Warwick.”

In one point at least (the angularity of the fruit) this last specimen shows some affinity to the pear-shaped fruited series which connects E. macrorrhyncha and E. Muelleriana (see p. 229).

The leaves, buds, and some of the fruits precisely match Mr. Baker's E. nigra, and I cannot separate them from the small-fruited form of E. Muelleriana, on the one hand, nor from E. eugenioides on the other. I think their proper place is transit between E. Muelleriana and E. eugenioides. These northern specimens connect with those from the (a), (b), (c) from the Armidale district, already referred to (p. 219).

Mr. Baker also records E. nigra from Cook's River, Sydney. I am of opinion that these specimens are referable to E. eugenioides, the size and shape of whose fruits is very variable in the Sydney as well as in other districts.

These difficulties of nomenclature and hesitancy to attribute some forms definitely to one species to the exclusion of others arises from the realisation, which presents itself to a philosophic mind, that in nature we have an infinite gradation of forms—a fact which is increasingly brought home to us as our knowledge of them increases. A knowledge of the oil-contents of the cells of the leaves is a contribution to such knowledge; but we must be on our guard that we do not allow ourselves to be unduly influenced by this, but should balance it fairly with evidence obtained in other lines of investigation.




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3. E. capitellata, Sm.

I have shown, in dealing with Victorian and South Australian specimens (p. 213), how difficult it sometimes is to separate E. Muelleriana from E. capitellata. Typical suckers of E. capitellata may be different enough. The test as to the coriaceous character of the leaves breaks down, e.g., I have very coriaceous leaves of typical E. Muelleriana from Wingello, N.S.W., while west and north coriaceous leaves of E. Muelleriana are particularly abundant. That E. Muelleriana and E. capitellata run into each other I have no doubt.

4. E. macrorrhyncha, F.v.M.

Turning to observations under E. macrorrhyncha, I am simply unable to separate E. Muelleriana and E. macrorrhyncha in some northern New South Wales and southern Queensland forms. The figures (10–13, pl. 38) will explain my meaning. Some of the northern forms may be looked upon by some botanists as referable to E. capitellata; indeed, I cannot say in what important character they differ from the Victorian-South Australian specimens referred to under E. capitellata.

The following notes on E. Muelleriana seedlings refer to the type plants in Victoria. I have already pointed out, however, that the seedling leaves vary:—

In E. macrorrhyncha the seedlings are also more or less beset with tufts of hairs, giving the stems a rough appearance, but in a less degree than the last-named species (E. capitellata). The leaves, at first opposed, are lanceolar in form, and slightly shiny. The seedlings of E. Muelleriana are as characteristic as those of any other species known to me. The stem and stalklets are slightly tufted with hairs, or are even smooth; the leaves rather long, lanceolar, pointed, and opposed throughout, even in seedlings of a foot or more in height, while their extremely shiny upper surface distinguishes this form from all the other species of this group [my italics, J.H.M.], being more marked even than in E. obliqua, from which the persistent opposition of the leaves readily distinguishes it.—(Howitt, Trans. Roy. Soc. Vict., vol. 2, pp. 92–3.)

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