― 272 ―


1. With E. oligantha Schauer.

Its closest affinity appears to be with this species, but E. oligantha has paler foliage, urceolate calyx-tube, which does not continuously taper into the pedicel, much shorter filaments, and capitate stigmas. The anthers of the two species are similar, but not identical. E. oligantha is described as shrubby (but later it may prove to attain tree size), but we know nothing of its bark and timber. The fruits of neither species are known.

2. With E. Spenceriana Maiden.

As a rule this species has thin, graceful, lanceolate leaves, but occasionally it has coarser foliage, e.g., the Stapleton, Northern Territory, plant shown at fig. 4, Plate 156, C.R. But even in that tree, which presents a good deal of similarity to a tree of E. Hillii, the foliage is not broad as a whole. Also, the bark of E. Spenceriana is not tessellated; it is a Box. The fruit of E. Spenceriana is small and of papery or angophoroid texture, which that of E. Hillii can never be.

3. With E. alba Reinw.

A large leaved, long petiolate species suggesting a similarity to E. alba. For that species Plates 105–7, C.R., may be referred to. But E. alba differs in buds and anthers, and in developing into lanceolate leaved forms.


(Continued from p. 259, Part XLVIII.)


Nanism or dwarfing may arise from more than one cause, or from a combination of them. As a rule, the most obvious factor is prevalence of strong winds, and where this is accompanied by shallowness of soil, we have a couple of important factors. It is notorious that trees become dwarf in exposed situations near the sea, and on high mountains; indeed, we can trace the diminishing size of a species according to the varying shelter individuals receive.

Examples of the effects of the strong sea air in diminishing size, taken almost at random, are, at First Point, near Kincumber, Broken Bay, New South Wales, where Mr. R. H. Cambage and I saw E. resinifera Sm. flowering at 4–5 feet, E. umbra R.T. Baker at 4–5 feet, E. paniculata Sm. at 6 feet. Normally these species are medium-sized to large trees.

F.—The Flowering of Eucalypts while in the Juvenile-leaf Stage.

“The generative maturity of plants is not connected immutably with a definitive stage of development.” There seem so many cases in which flowering and fruiting have been found to occur in the opposite-leaved stage that it seems fair to assume that further experience will show that it may occur in very many more—perhaps in all species.

Naudin's First Memoir, 347 (1883) says, after speaking of the adventitious leaves “which take on the appearance of the juvenile stage. …,” “this retrogression towards anterior forms, and which is like a partial rejuvenation of the tree, is not an obstacle to the flowering; these branches of juvenile aspect sometimes flower and ripen the fruits as well as those of the adult form.” He seems to have been the first botanist who made this observation.

In 1906 Dr. L. Diels published his “Jugendformen und Blütenreife im Pflanzenreich,” and I cannot do better than quote portions of a review of it by C. R. Barnes which appeared in the Botanical Gazette, vol. 45, p. 137 (February, 1908). The work deals, inter alia, with the question of precocious blooming, and the genus Eucalyptus is illustratively employed.

An interesting discussion of the relations between the vegetative form and the flowering period of plants is presented by Dr. Diels. … The questions with which the book deals were raised by the author's travels in West Australia in 1902. After his return he examined the literature, and made further investigations to throw light upon the problems of form in the plant kingdom. He has gathered together

  ― 274 ―
a considerable number of examples of the relation between form, blooming time, and external conditions. These he presents and discusses in his usual luminous fashion. He has even cited briefly analogous phenomena, not a few from the animal kingdom.

The thesis of the book is that the generative maturity of plants is not connected immutably with a definitive stage of their development, as has been so widely held. A certain minimum of nutritive preparation is presupposed; but once this is passed, there is a broad variation zone in which blooming occurs. Its appearance is dependent upon complex, largely unknown conditions, an important part of which, however, are external. The vegetative ontogeny depends upon the co-operation of autogenous and exogenous (an excellent substitute for the awkward term “aitiogenous”) factors; for the rudiments of the vegetative organs have many possibilities, and which one is realised is determined by the environment. The mature form of the entire organism is thus a product of vegetative ontogeny and of generative maturity, both of which factors are variable, though their variability is not in the same direction. True, the development of vegetative structures usually ceases at blooming, but this is the only place where the two lines of development, the vegetative and the generative, are inseparably connected. Elsewhere they are free and independent of one another, and each varies after its own manner. In this connection of two variable factors lies an important impulse to increase the manifold forms of the plant world. For the conditions which help to regulate the succession of leaf forms and floral maturity change with the changes of climate in space and in time, giving rise to local geographic species and allowing true species to arise in the course of time. Their features attain heritability, and become therewith a source of new lines with new possibilities.

A new term, “helicomorphy,” is suggested to comprehend Goebel's two terms for the two-leaf forms in heteroblastic species, the juvenile forms and successive forms. In the course of a short chapter on the phylogenetic significance of helicomorphy, the author pays his respects to the famous “biogenetic law,” that ontogeny recapitulates phylogeny, in these terms: “In the botanical field it has absolutely no (nicht einmal immer) heuristic value, and whoever allows himself to be led by it will at most succeed in satisfying the needs of his imagination.”

In the genus Eucalyptus we are accustomed to see—

  • 1. Plants flowering when in the mature lanceolate-leaved stage. The juvenile leaves may be, and usually are, of a different shape. This is heteroblasticity.
  • 2. In a few cases the leaves maintain their juvenile form through life. (Isoblasticity or homoblasticity.)
  • 3. In a number of cases, and careful observation increases the number from time to time, we find plants which normally fall under (1), flower as regards individual branches, while in the juvenile stage.

At p. 97 of Dr. Diels' work already referred to, he says (translation):—

Everywhere in Eucalypts are shown close relations between juvenile forms and flowering maturity. It will be a very useful work for the Australian botanists to add new facts by observation in the field and in cultivation. Thereby it will perhaps also be possible to find out the conditions, of which we know very little at present. There is at least one fact which manifests itself empirically: The number of forms which flower while their foliage is in the juvenile state is specially numerous in regions where the surrounding medium is at a considerable distance from the optimum of the genus. (N.B.—I have dealt with the question of Optimum at Part 69 of my “Forest Flora of New South Wales.”—J.H.M.). The cool regions of Tasmania are rich in such forms. The dry plains of the North Australian sandstone tableland possess such species, and they are also found in the dry heaths of south-west Australia, which follow the interior border of the winter-rain region.

At. p. 17 he says:—

The reigning Australian genus Eucalyptus is marvellously elastic in the condition of growth and flowers. The most important instances will be given later (p. 88–98); for the present I will mention only a few cases given by Mueller, and from my personal observations in South-West Australia.

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He then proceeds to quote the cases of E. cordata, tetragona, redunca, marginata, and occidentalis.

“Flowering in a shrubby state” a (favourite expression of Mueller's), may not be identical with flowering while the leaves are in a retarded or juvenile state, but in a number of cases this is so. Of course some species are normally shrubby, and not because of nanism. In the following list I will indicate by (S) where I do not give further information, whether I have actually seen, or it has been reported to me, that the flowering is in the juvenile-leaved state.

E. Baeuerleni F.v.M. “Flowers at 5 feet.” (W. Baeuerlen.)

E. Beyeri R. T. Baker. A tree apparently referable to this species. See Part XLVIII of the present work.

E. Blakelyi Maiden. See figure 1, Plate 134, Part XXXII, for a specimen at Hill End, New South Wales, flowering in the juvenile stage.

E. Bosistoana F.v.M. Under the name E. Nepeanensis, R. T. Baker has described a new species which is merely E. Bosistoana flowering while some of the foliage is in the juvenile stage.

E. calophylla R.Br. “At the east end of the Stirling Range of Western Australia, I found E. calophylla as Maalok, only 5 feet high, while in Red Gum Pass (crossing the Range) the trees were very large and one decaying trunk between 5 and 6 feet in diameter lay on the ground.” (Dr. A. Morrison.) In the Stirling Range district I also have seen this species flower in a dwarf state. Dr. G. P. U. Prior, of the Mental Hospital, Rydalmere, Sydney, informs me that he has flowered E. calophylla var. rosea in two years from the sowing of the seed.

E. calycogona Turcz. Figured at D, Plate 9, Part III, we have an instance of inflorescence with juvenile foliage.

E. celastroides Turcz. See fig. B, Plate 10, Part III.

E. cinerea F.v.M. (S.)

E. cordata Labill. is a medium-sized tree, but often it remains shrubby. Mueller writes (Eucalyptographia) `I have rooted specimens before me, hardly 3 feet high, but nevertheless bearing flowers and fruits.”' (Jugendform., p. 17.)

E. cosmophylla F.v.M. This is a medium-sized tree from Mount Lofty, South Australia. Dr. J. B. Cleland sowed seeds on 12th May, 1912, at Neutral Bay, Port Jackson. The plants flowered in 1917 and 1918. There were flower-buds on 25th October, 1918. The height was 10 feet 6 inches on 8th December, 1918.

E. diversifolia Bonpl. A cultivated plant in the Botanic Gardens, Sydney (W. F. Blakely, March, 1920).

E. dives Schauer. Mr. A. D. Hardy draws attention to the precocious blooming in this species in Victoria. See Proc. Roy. Soc. Vict., XXIX (New Ser.) 170. Bentham pointed out the flowering of this species as a tall shrub. (S.)

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Eudesmiæ. It seems to me that all Eudesmiæ flower in the opposite-leaved stage.

E. fasciculosa F.v.M. (S.) See Part XIV, p. 140.

E. ferruginea Schauer (S).

E. Foelscheana F.v.M., flowering at 18 inches. (S.)

E. gamophylla F.v.M. (S.)

E. gigantea Hook. f.

I have repeatedly seen this species flowering profusely when about 6 feet high, sometimes when not more than 3 feet, and on several occasions when it had reached a height growth of between 2 and 3 feet. As this species rarely suckers, it appeared to me that the early and profuse seeding powers were a compensating characteristic of the species. (W. A. W. de Beuzeville, Forest Assessor, Forestry Commission, Sydney.)

In another letter Mr. de Beuzeville says: “Regarding your inquiry as to the state of the foliage of this species when in the early flowering stage of 2 or 3 feet, I may say that you are quite right in your impression that it flowers in a juvenile-leaf stage. I have often seen the flowers on these flowering saplings fully 4 inches broad and about 5 inches long.” This, therefore, is to be added to the list of tree species which also flower in a shrubby state, and also to the list of those that flower in a juvenile-leaved stage. (Maiden, in Journ. Roy. Soc. N.S.W., LI, 449, 1917.)

E. globulus Labill. Mueller (Eucalyptographia) says, “On the storm-beaten rocks of Wilson's Promontory I have seen E. globulus profusely in flower and fruit, though dwarfed by exposure to the size of a mere shrub, when almost within the reach of oceanic spray.”

Mr. A. D. Hardy sent me a twig of reversionary foliage from an introduced street-tree at Stawell, Victoria. The tree is of normal appearance, and bears buds, flowers and fruits plentifully. Near a fork were reversionary shoots, all fruit or flower bearing.

E. gracilis F.v.M. See fig. 1. Plate 12, Part III, of this work.

E. Houseana (W.V.F.) Maiden. We may have inflorescence both with mature and juvenile leaves in this species. See Plate 204, Part L of this work.

E. Kybeanensis Maiden and Cambage. Flowers in juvenile stage. See legend at p. 185, Part XLVI of the present work.

E. leucoxylon F.v.M. Mueller (Eucalyptographia) has seen the species flowering in a shrubby state, “even when the leaves were still opposite.” Flowered and fruited freely at 4–6 feet on very poor shingly ground at Bacchus Marsh, Victoria, see Part XII, p. 90.

A red flowering form from Murray Bridge, S.A., collected by himself, had seed sown by Dr. J. B. Cleland at Neutral Bay, Port Jackson, 14th November, 1915. It flowered at a height of 11 feet 6 inches from 26th October, 1918, to 3rd December, i.e., at three years old. The flowering twigs, as seen by me, were not, however, in the juvenile-leaf stage.

E. macrocarpa Hook. A dwarf Western Australian species. (S.)

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E. marginata Sm. “The typical tree-form is confined to the more moist country, and will not be seen any more where the yearly rainfall is below 75 cm., but occasionally one will meet there with shrubby forms. (Dr. Diels.)

E. melanophloia F.v.M. (S.)

E. melliodora A. Cunn. This is a precocious flowering species, and when it flowers in a shrubby state the leaves are often large. (S.) See Part XIV, p. 135.

E. Moorei Maiden and Cambage. (S.)

E. occidentalis Endl. (Quoted by Diels.)

E. perfoliata R.Br. See fig. 3a, Plate 180, Part XLIV, showing that it may flower in the juvenile stage.

E. Planchoniana F.v.M. Flowers at Stradbroke Island, Queensland, as a stunted bush of a few feet (C. T. White).

E. polyanthemos Schauer. Flowering as a shrub of 8 or 10 feet, at Quiedong, near Bombala, New South Wales (W. Baeuerlen, March, 1887).

E. præcox Maiden. See Part XXVII, p. 131 (last paragraph but one), and fig. 13e, Plate 112. Inquiry is going forward as to whether the remarks under E. Bosistoana (Nepeanensis) apply here.

E. pulverulenta Sims. (S.)

E. pyriformis Turez. (S.)

E. Raveretiana F.v.M. Flowers when only 10 feet high (Mueller in “Eucalyptographia.”)

E. redunca Schauer. (Quoted by Diels.)

E. Risdoni Hook. f. (S.)

E. rostrata Schlecht. Mr. A. D. Hardy draws attention to a case of precocious blooming in this species near Melbourne. (Proc. Roy. Soc. Vict., xxix, (New Ser.), 171).

E. rubida Deane and Maiden. For figure of this species flowering in juvenile stage at Kangiara, near Bowning, New South Wales, see fig. 4a, Plate 110, Part XXVI.

E. setosa Schauer. See Plate 158, Part XXXVIII.

E. tereticornis Sm. This occasionally flowers in the broad-leaved (juvenile) stage.

E. tetragona F.v.M. (Quoted by Diels.)

E. trachyphloia F.v.M. See Bailey's proposed form fruticosa discussed at Part XLII, p. 43.

E. umbra R. T. Baker. Some of the juvenile leaves very broad, but all rather thin and paler on the underside. Mr. Cambage and I found it fruiting as a dense scrub of 3–4 feet high on the summit of First Point, Kincumber.

E. uncinata Turcz. is one of the species in which the juvenile form of foliage often remains side by side with the mature foliage.

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E. vernicosa Hook. f. (S.)

E. viminalis Labill. Beyond the Blue Mountains, New South Wales, e.g., Cox's River to Fish River, Mount Blaxland to Rydal, Sidmouth Valley (all R. H. Cambage and J.M.H.), we have collected this species with fruits and juvenile leaves on the same twig.

Mr. A. D. Hardy figures an example of precocious fruiting amongst resting buds in E. eugenioides in Gippsland. He says he has also seen it in E. obliqua. I have seen it in E. eugenioides in the Sydney district. (Proc. Roy. Soc. Vict. xxix (New Ser.), 172, and Plate 13, 2.)

Eucalyptus alpina was grown in the Centennial Park, Sydney, from seeds obtained from the Victorian Grampians, and it is one of the surprises of acclimatisation that it succeeded there admirably. Mr. A. A. Hamilton, in whose care the tree was, informs me as follows:—

The first buds which appeared developed slowly, and at the end of one year were still diminutive. In the second-flowering season a further set of buds appeared, which behaved in a similar manner to those of the first year, the latter increasing in size, but still remaining unopened. This again occurred in the third year, three separate sets of buds in different stages of development appearing on the plant at the same time. At the close of the third season the first year's buds flowered, and finally fruited nearly four years after the buds first appeared on the plant. At this period there were four distinct phenological stages of floral growth present.

G.—Dominance or Aggressiveness of Certain Species.

This is a subject which has scarcely occupied the attention of Australian foresters yet, or at all events they have rarely written about it.

Some years ago I pointed out to Mr. Golly, the Superintendent of the Gosford Nursery, New South Wales, a flourishing tree of E. numerosa Maiden, in a border adjacent to the boundary fence. A slender species, it seemed to be flourishing as well as any species in the border. I several times during various years visited this tree, because of the personal interest I took in the species.

In 1915 I was present at the dedication of the Strickland Forest, a few miles away, and pointed out to some people the way in which this species (a southern one) was taking possession of a fairly large area of the forest, its spread being far greater than when I had visited the forest a few years previously. I pointed out that this was the first Eucalypt I had known to behave in such an aggressive manner.

I was therefore much interested to read that Dr. L. Cockayne, F.R.S., in his “New Zealand Plants and their Story,” gives an example of the aggressive character of a species of Eucalyptus.

At Waitati, near Dunedin, on the land belonging to the Mental Hospital, stands a fine example of a kind of Stringybark (Eucalyptus numerosa), more than fifty-eight years of age. Originally the vegetation of the area was mixed Taxad forest, but this has been replaced by a close growth of Manuka thicket (consisting of various low shrubs). Some years ago this thicket was burned in the neighbourhood of the tree, and a young forest of gums several acres in extent has sprung up, the new ground and the potash from the fire being eminently suitable for the germination of the Gum-tree seeds. In 1910 the Gum saplings

  ― 279 ―
grew extremely closely. Their height was from 40 to 50 feet. Some were half a foot in diameter, while others were extremely slender. Thousands of Manuka (Leptospermum scoparium) seedlings sprang up along with those of the Gum; and it must not be forgotten that Manuka, far more than most of the indigenous plants, can reproduce itself again and again after burning, and can exclude almost all other vegetation. But in this case the great rapidity of growth gave the Gums the victory, and eight years ago only a little Manuka remained near the margin of this remarkable and quite natural forest growth.

But this is only one phase of dominance. We want observations, as quantitative as possible, showing the way in which various species attain large size and crowd out or smother other species. The Taxonomic portion of this work now enables foresters to recognise the Eucalypts. These remarks should be read in connection with Coppicing, in Part XLVIII, p. 249, where another phase of Dominance is incidentally referred to.

In the photograph, to be reproduced later, supplied by Mr. C. J. Weston, Afforestation Officer of the Federal Territory, we have a lesson taught, as regards a few species, in a limited area, and it shows how E. Macarthuri has dominated certain species.

But what we mainly want are observations in regard to what may be termed the natural dominance of the trees of the forest, in order that this factor may be taken cognizance of in the plans for commercially working the forest.

H.—Natural Grafts.

1. Cohesion of Branches.

See an Appendix entitled “On some Natural Grafts between Indigenous Trees,” to my “Forest Flora of New South Wales,” vol. vi, pp. 79 and 287. This is based on an earlier paper by me in Journ. Roy. Soc. N.S.W., xxxviii, 36, (1904). Most of the references are to adhesion, not cohesion. I give some cases of true cohesion—that is to say, the branches of only one species being concerned.

See also a fine example of a natural graft in E. tereticornis on the original. Bathurst, New South Wales, road, between Sidmouth Valley and Rainville Creek. The photograph (April, 1909) is by R. H. Cambage, and is reproduced in my “Forest Flora of New South Wales,” vol. vi., p. 287.

In Vict. Nat., xxvii, 207 (1911) is a note by Mr. J. W. Audas, with an excellent photograph of cohesion of branches in E. elœophora F.v.M., locally known as “Grey Gum.” It is near the Beaconsfield State School, Victoria, and was pointed out by Mr. McCann. The tree is about 15 feet in circumference at the base, and attains a height of about 50 feet. It forks about 10 feet from the ground, and unites again at about 25 feet. After this union four large limbs spread out. The junction is quite 3 feet by 3, and the limbs growing thereon are much thicker than those below the union.

In Vict. Nat., xxxviii, 13, June, 1921, there is a statement by Mr. Audas that he has seen in the Balangum Ranges, Grampians, Victoria, a Yellow Box (E. melliodora) and a Grey Box (E. hemiphloia var. microcarpa), which have different root-systems. The usual circumstance is that the trunks fuse only a few feet from the ground, and,

  ― 280 ―
at a little distance, the tree appears to have a composite trunk with two kinds of bark, and to have two kinds of foliage, as represented by two large branches of the different species concerned.

There is a fine example of this inarching of branches, 12 inches in diameter, in E. hæmastoma var. micrantha in the Federal Territory, on the Queanbeyan-Uriarra road, near the saddle of Mount Stromlo. Mr. C. J. Weston pointed me out the tree and sent the photograph (February, 1920), which will be subsequently reproduced.

There is another illustration of cohesion of branches in the figure of E. rostrata by A. D. Hardy, Plate XI, Proc. Roy. Soc. Vict., xxix (New Series), 167 (1916).

“An excellent instance of fusion of shoots (post-genital) was observed in the case of E. salmonophloia; two cross-bars occurred, one close above the other; a very rare case.” (“Principles Plant Teratology,” Worsdell, i, 118).

It will be observed that all the Eucalypts quoted are Gums, or, if rough barked on the trunk, with smooth branches. In an allied genus, Angophora, A. lanceolata is perhaps the commonest tree in Eastern Australia to show the phenomenon, and that is a smooth bark also. In the case of the rough barks, it is fair to suppose that the fusion took place at an early stage of the plant's history, before the rough bark had developed.

“Naturally grafted branches are fairly common on Beech, Oak, Holly, Lime, Willow, Yew, and Scots' Pine, whilst they may also be noted on many other trees.” (“Natural Grafting of branches and roots,” by W. Dallimore, Kew Bulletin, 1917, p. 303). Mr. Dallimore discusses the way in which this grafting has been brought about in certain cases. Speaking of the friction between two branches, caused by the wind, he points out that a good deal of tissue may be destroyed, and all the time nature is trying to repair the injury by forming patches of callus on both branches, at those places where friction is least active. As the branches become heavier and movement ceases, the patches of callus grow together, and eventually a strong union is effected between the two branches. The paper is suggestive, and should be referred to.

2. Adhesion of Branches.

Under Cohesion of Branches,” at p. 279, I have quoted a paper from my pen, and it will be seen that the Natural Grafts there enumerated are vastly more numerous in the case of Adhesion, i.e., where two different species (and more rarely, genera) are concerned. I will content myself with a few supplementary notes.

Following is a relatively early reference to natural grafts. “If nature does not admit of crossing in the genus Eucalyptus, it certainly encourages that of grafting, for, in the neighbourhood of Mudgee, the Apple (Angophora intermedia) may be grafted naturally on E. rostrata, whilst, on the Richmond Common a similar eccentricity may be seen on E. tereticornis.” (Rev. Dr. Woolls in Proc. Linn. Soc. N.S.W., xvi, 61, 1891.) I have not seen the reputed Mudgee graft, but that on the Richmond Common was a false graft, in other words, no graft at all. See my “Forest Flora of New South Wales,” vol. vi, p. 79.

  ― 281 ―

See also a natural graft between E. obliqua and E. viminalis at Turritable Creek, Macedon, Victoria, reported by A. D. Hardy. (Proc. Roy. Soc. Vict., xxix, (New Series), 166.)

Mr. A. D. Hardy also gives a case of heterotropy (reversed direction of growth of branch), in the form of a drawing of a branch of a reputed hybrid of E. hemiphloia X melliodora, between Stawell and the Grampians, Victoria. (Plate 12, Proc. Roy. Soc. Vict., xxix (New Series), p. 169.)

There was also reported to me as a natural graft E. maculata (Spotted Gum) (this was green) and E. paniculata (Grey Ironbark) (this was dead). The trees were at Cessnock, New South Wales, and the observer, Mr. F. G. McPherson, District Forester, Wyong, New South Wales. I have a photograph, but in view of the death of the Ironbark the graft does not appear to have been perfect, and it is probably one of the so-called false grafts, i.e., where one tree grows in another, the latter being a sort of container or flower-pot.

The late Dr. G. V. Perez, of Teneriffe, who died in January, 1920, was a man whose work was admired by horticulturists throughout the world. He took the liveliest interest in Australian plants. Amongst others he cultivated E. ficifolia and E. calophylla. Following are extracts from some of his latest letters, and which refer to adhesion of branches (grafting by approximation, approach, inarching, are more or less synonymous terms, though in strictness, inarching only takes place when scion and stock are growing on their own roots).

In order to preserve a very beautiful Eucalyptus hybrid, which I am growing from seeds sent from Sydney as E. ficifolia (cherry-coloured) (this is E. calophylla var. rosea.—J.H.M.), I am grafting by approximation, placing the stock in a large and long bamboo; the method succeeds very well, and I should say that to preserve any pretty shade of colour it will be valuable. I am going to employ as stock the hybrid calophylla x ficifolia, as E. ficifolia is much more delicate in the bad soil I have here, and besides the “Cherry” I wish to preserve is a hybrid, which does not breed true from seeds; I have thought that what I have written may possibly be of some interest. (31st March, 1919.)

I shall now endeavour to obtain several plants of one which you sent as E. ficifolia, and which is certainly a hybrid, often referred to in my correspondence with you as “Cherry” colour (calophylla var. rosea.—J.H.M.), and most beautiful and floriferous, which began to flower when only four years old, and the progeny of which began to flower as early as two years old, some of them being white, some resembling the parent plant, and some rosy-pink (on Mendelian lines probably.—J.H.M.). The colour is so beautiful that it is worth while preserving by grafting by approximation, by the method above named, and grafting on its own stock; I have already two successfully grafted and planted out, but on (?) true ficifolia, which is not such a good stock.

…. with reference to what I wrote about grafting E. ficifolia by approximation in large and long true bamboo tubes, allow me to add that a small tree grafted in this manner, and which is only about half a yard high, and which has only been in the ground about one year, is about to flower; its parent, the seeds of which were sent by you, is of a beautiful fire or orange colour, and I presume it is the true ficifolia, which, according to you, is often of this colour. (18th June, 1919).

In my last letter I alluded to a tiny Eucalyptus which I had grafted by approximation; it has flowered. It is of the fire or orange kind. If there is any novelty about this kind of grafting of coloured Eucalyptus to preserve the pretty kinds, perhaps you would like to know that it has been a most successful way of grafting in my hands; I first grow the stock in a long and large true bamboo tube, and attach it to the tree I wish to graft on and propagate. (5th July, 1919.)

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J.—Artificial Grafts.

1. Budding and Grafting.

I do not know of any successful Australian experiments with adult Eucalyptus plants. In a few cases I have heard of experiments being made, but they have usually been abandoned before completion of the experiment.

Following is an account of some experiments by French horticulturists:—

M. Felix Sahut gives a remarkable account of a Eucalyptus which, planted at Lattes in 1864, resisted 32 degrees Fahr. of frost during the memorable winter of 1870–1, nor did the tree suffer in any way, and even its leaves remained intact. It had been raised from a seedling among seed of E. Risdoni, and its identity was never traced. It grew to a height of nearly 40 feet during its comparatively short life, for at the age of twenty years it gradually began to show signs of weakness, and ultimately it died.

This tree, which had been provisionally named E. Lattensis by M. Naudin, indicated a species possessing cold-resisting qualities, but as it never blossomed, M. Sahut's foresight led him to graft it on an allied species, with the view to its cultivation as an ornamental tree in more northern parts of France.

Two methods were employed, one, the cleft graft, with moderate results only, and the graft by approach, or inarching, with much greater success. The stock being more susceptible to cold than the scion, the operation was purposely made as near as possible to the root. The union of the plants was practically perfect, and five or six dozen plants developed vigorously and with great promise. Some of them grew to a height of 6 feet during the first year, but during the next season they all began to fail, and at the end of the third year not one was alive.

The operation of budding was not tried by M. Sahut in these experiments, because he did not think it would succeed, and it is interesting to note that this method has been adopted with good results elsewhere. The Revue Horticole published, in 1893, an account of work of this character conducted in Palestine by M. Justin Dugourd, who budded E. globulus on E. resinifera. The former species is one with spreading roots, and is less resistant to the influence of the wind, &c., than the latter, which was used as the stock, because it grows into a strong tree.

It appears to be necessary for the complete success of this operation to support the scion in some suitable manner, so that the sap may the more readily reach it. As the stock increases in growth it is also desirable to remove any shoots which it may produce, unless the operation is unsuccessful, when the subject may then be allowed to grow. (Gard. Chron., 11th March, 1899, p. 145.)

2. Grafting by approach in the Seedling stage.

This operation may be either cohesion or adhesion, and it leads to such important and, perhaps, practical results, and therefore is worthy of brief consideration under a separate heading.

Grafting by approach in Eucalyptus is easy when the plants are little past the cotyledón stage, according to some experiments by Mr. C. J. Weston, Afforestation Officer, Canberra. In practice they sometimes result in pans of mixed seed, two diverse seedlings being accidently pressed together by the fingers in the operation of potting up.

In the nursery rows at Canberra are three sturdy plants of E. rubida-maculosa. When I saw them in July they were about 3 feet high, and spreading. One half of each plant has the typical rubida character, and the other half of the plant the typical maculosa character. Stripping the soil from the roots shows perfect fusion of the two trees. This grafting by approach or fusing of two species by pressure applied at a critical time could also hardly be avoided by the agency of animals treading amongst young seedlings.

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I published the above note in Journ. Roy. Soc. N.S.W., liii, 21, (1919), as I thought Mr. Weston's experiments should be put on official record. An illustration will be furnished in due course.

Here, I think, is the key to the most perfect case of fusion or adhesion I have ever seen in my life, viz., that brought under my notice by Mr. Chappelow of a White Gum and a Stringybark illustrated (as regards a section of the timber) in my paper, Journ. Roy. Soc. N.S.W., xxxviii, 36 (1904). See also my “Forest Flora of New South Wales,” vi, 79. It seems to me much more likely that so complete a fusion of two species would take place at a very early stage of the existence of the two plants than by the rubbing together of woody stems or branches later on. As Eucalyptus trees are increasingly grown artificially in Australia, we may expect to see more of these grafts originating in the potting shed. Perfect natural grafts of the Chappelow type are exceedingly rare, and it seems to me that my theory of fusion as young seedlings by the trampling of native animals or of stock is worthy of consideration.


Fasciation of branches is not common in Eucalyptus, or at all events it must be rare, for I have not come across a record. A case of fasciation in young suckers of E. gracilis was sent to me from Lake View, Griffith, Line 61 (N.S.W.) by Mr. W. D. Campbell, L.S., in 1918.

L.—Tumours and Galls.

The literature on this subject, as regards Eucalyptus, is very scant. Not only the most important paper but almost the only one, is “On certain shoot-bearing Tumours of Eucalyptus and Angophoras, and their modifying influence on the growth habit of the plants,” by J. J. Fletcher and C. T. Musson, in Proc. Linn. Soc. N.S.W., xliii, 191, with many plates.

They quote Clayton O. Smith, “Further Proof of the cause and infectiousness of Crown Gall” (Univ. California Publications, Agric. Experim. Station Bull. No. 235, December, 1912), as the first to draw attention to the fact that the stem-nodules in a certain species of Eucalyptus are axillary, and that certain stem-nodules arise from infection by soil-bacteria. “In Eucalyptus seedlings the natural knots often appear opposite each other where the cotyledons have previously attached, also the Quince knots appear first at the node about the old leaf-scar. All the evidence we have goes to show that some injury or weakness is necessary for infection to take place.”

Clayton O. Smith, op. cit., p. 549, published the figure (21) which will be duly reproduced. The legend is “Artificially caused galls on forest Red Gum (Eucalyptus tereticornis). Crown gall has not been known to attack the various species of Eucalyptus

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in nature. The significance of swellings found frequently at the crown of young Gum trees is not yet understood. They do not appear to be detrimental to the tree.” A further note on this crown gall will be found at p. 552 of the work quoted.

Forest Red Gum (Eucalyptus tereticornis). Fig. 21. Seedlings of 4 to 6 feet were inoculated. The first successful inoculations were made May 16, 1910. On March 25, 1912, there was one large knot and one very small one at points of inoculation. September 2, 1911, inoculated a seedling about ½ inch in diameter. February 20, 1912, there were two small knots. On March 26, 1912, one of these knots had grown rapidly in size, the other had not changed.

Inoculations were made on small seedlings July 29, 1910 on the branches. Typical roundish knots or galls had developed on September 5, 1910.

The appearance of a Eucalyptus nodule (or rather a pair of axillary stem-nodules still unfused) may be seen in the figure of one in E. paniculata, see fig. 12, Plate 57, Part XIII of the present work.

Fletcher and Musson (p. 198) say:—

Were it not that, by a fortuitous combination of circumstances, the axillary stem-nodules are able to fuse in pairs, the fused pairs to concresce, and the reinforced, composite, stem-encircling tumours thus enabled to incorporate roots, and so last for some considerable time, or even permanently, both the nodules and any shoots they might develop would be short-lived and abortive, as they actually are in refractory seedlings, and as the shoots on the lower pairs of concrescences also are. …

But in the natural inoculations in the lower axils of the young seedlings of Eucalypts, which furnish some of the most valued hardwood timbers, we are inclined to think that the organisms are confined to the out-growths, and the circling tumours to which they give rise, and probably do not invade the tissues of the seedlings. The tumours do not kill the seedlings, or even seriously damage their tissues. They are a drag on the normal development of the plants, especially so when shoots do not develop, and by interfering with the water-supply, and also by their shoots preventing the development of the normal branching. In the Mallees, so much water is intercepted by the tumours that the seedling-stem is dwarfed; and, by the persistence of the shoots, the growth habit is permanently distorted, so that the plants are prevented from realising their potentialities as trees. The seedling-stem may possibly be sometimes crowded out and got rid of. But the stem-nodules, as well as the composite tumours to which they give rise, are complex tumours, composed of both somatic cells and germ cells; and the latter are totipotent, because in the persistent-composite tumours of the Mallees, the tumour-shoots complete their growth, flower and fruit, and produce seed. Even in the non-Mallees, if the seedling-stem is lost, two tumour-shoots may take its place, attain to tree-size, and flower and fruit. But they do not prematurely disclose their embryonic possibilities in the way that some of Erwin Smith's artificially-produced monstrosities did. Also, the production of these tumours in Eucalyptus under natural conditions is a matter of long standing. The Mallee scrubs, which must have been the development of centuries, were in their prime when civilised man first saw them, nearly 101 years ago.

Then follow a number of interesting references to Mallees, arranged in chronological order, particularly as regards the “root”—the “Mallee-roots” which form an important portion of the fuel supply in South Australia and those portions of Victoria and New South Wales adjacent thereto.

The authors (pp. 204, 228) state that they have met with six species of Eucalypts exempt from tumours or stem-nodules, viz., E. oreades R. T. Baker, E. pilularis Sm., E. sp. (from foot of Blue Mountains, New South Wales, on the western side), E. giganteo Hooker, E. regnans F.v.M. var. fastigata. I hope the paper will direct the attention of Australians to phenomena which have only been imperfectly studied as regards

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the morphology of the widely distributed tumours or galls themselves, and which could only have been studied as to causation since the development of the science of bacteriology.

During the last twenty-five years at the Botanic Gardens, Sydney, and at the auxiliary State Nursery, Campbelltown, I have caused to be raised many thousands of Eucalyptus seedlings for distribution to public institutions. The number of species grown at Campbelltown is relatively small, but at Sydney (chiefly for the colour-drawings of seedlings by Miss Flockton for many years, and latterly by Miss Ethel King, an enormous number of species, perhaps 150, has been grown from time to time, and in many cases these have been kept in pots for years until pronounced mature leaves made their appearance. In course of time, research students will continue or promote the good work of Messrs. Fletcher and Musson, and I hope that the enormous wealth of nodule material to which I have alluded (and which is far in excess of any material of the same kind I have ever heard of) will be used for study.

The following brief bibliography concerning galls in plants other than Eucalyptus may be suggestive. It chiefly refers to the dreaded Crown Gall, which works such devastation in economic plants:—

Bulletin 213, on “Crown Gall of Plants; its cause and remedy” (Bureau of Plant Industry, U.S. Dept. Agric., 1911).

“Chemically induced Crown Galls,” by Erwin F. Smith (Proc. Nat. Acad. Sciences, Washington, iii, 312 (April, 1917)). “A fuller account, accompanied by photographs and photo-micrographs, will be published in the Journal of Agric. Research.” See also Abstract in “Current Opinion” (Philadelphia) for March, 1918, p. 193.

“Plant Cancer,” Missouri Bot. Garden Bull., May, 1919, p. 51. A useful short article, with a few illustrations and some bibliography.

In “The Garden” for 12th July, 1873, is a brief article, with a remarkable illustration, on “Swollen-stemmed Irish Yews.” The specimens, bearing large tuberous bodies between the stem and the proper roots, were obtained from cuttings. The plants were generally under 2 feet in height, while those of normal growth, of the same age, averaged about 5 feet; all, however, having the same healthy appearance. The tubers averaged from 8 to 12 inches in circumference, with a ligneous structure throughout, but showing large annual rings or growths, and covered with bark, having numerous roots proceeding from the under surface.

Mr. E. Breakwell, B.A., B.Sc., has very kindly given me a memo., which has been reproduced with little alteration and few additions, in the following statement.

Bulbous and tuberous stems may be caused either by (1) insect invas on, forming galls, (2) fungus invasion, (3) xerophytic conditions, and (4) qualitative influence of correlation.

(1) Insect invasion. See Goebel's “Organography of Plants,” Part I. Goebel points out that galls are due either to a material excreted from the unfertilised, or

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from the fertilised egg, and that the material may be the same in both cases, or in some cases by a larval stimulus. The protection to the insect in the gall is effected partly mechanically, partly chemically—especially by a copious formation of tannin—but the protection is not absolute. He emphasises two points—

  • (a) In general no tissue elements appear in the anatomical structure of the gall which do not exist elsewhere in the plant under other conditions.
  • (b) All the more highly differentiated galls are produced out of juvenile tissues caused to develop in an abnormal way by gall insect. The more complex the gall is, the earlier must the influence producing it be exerted on the plant tissues.

(2) Fungus invasion. See Annals of Botany, vol. xxiv, p. 537, July, 1910, by T. Reed. The writer points out that Bernard discovered, by inoculating the cortex of the roots of young plants of Solanum tuberosum with the spores of the fungus Fusarium, he produced a greater yield of tubers than if not artificially inoculated. This means that although the stem is removed from the roots, the former becomes infected. Bernard tentatively suggests that the fungus may thus operate by giving rise to soluble products which in some mysterious way cause the underground stems to swell up and accumulate vast reserves of carbohydrates, &c.

“The roots of Podocarpus are covered with small tubercles formed by a Mycorrhiza, which probably assists in the nutrition of the plants, especially when young. (“The Flora of South Africa” (Marloth), i, 103, with fig.)

(3) Xerophytic conditions. See Warming—“Aecology of Plants,” p. 124. Bulbous and tuberous plants are mainly confined to Liliaceæ, Iridaceæ, Amaryllidaceæ, and other families growing in dry countries, particularly in South Africa. Many tubers consist of root and stem combined, as in the case of some shrubs in the South American savannahs.

(4) Qualitative influence of correlation. Goebel, “Organography of Plants,” Part I, p. 215, points out that if a certain part of a plant be affected (by wounding, e.g.) other parts will be affected. Knight produced tubers from aerial roots, by removing the subterranean stolons at an early period or by interfering with their connection with the aerial parts. He produced tubers on the top of the aerial shoots, the points furthest separate from the normal position of formation of tubers.

M.—Protuberances of the Stem.

In reply to a correspondent, I intimated that the matter of reserves of liquids in trees is principally in the Apple Tree (Angophora), a genus closely allied to Eucalyptus. It is also found in a number of Eucalypts. It arises through the irregular shrinkage of the rings of timber, and these get more or less filled with gum—or kino is a more correct term—and when shrinkage proceeds further, being sometimes helped by bush fires,

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these cavities may cause shelling; if they proceed further they are large enough to fill a bucket. As a rule, these cavities contain liquid more or less astringent, because of the presence of the kino of which I have just spoken. In the case of the Cider Gum of Tasmania (E. Gunnii), the liquid is watery and so little astringent that it can be drunk. In many cases the liquid gets into the cavity through lodging in the fork of the tree or trickling through a crack of the wood. To some extent this watery liquid would be added to by the sap, but I think that the quantity of that is negligible. There is no evidence that the liquid benefits the tree or otherwise. It is not a disease; it is simply an evidence of mechanical shrinkage of the timber. Some of the Bloodwoods (E. corymbosa and allies) have the cavities mainly filled with kino.

I have referred to this phenomenon of swollen stems, often liquid retainers, at some length in Part lxiii, p. 119, of my “Forest Flora of New South Wales,” in regard to the following species:—E. Gunnii, E. maculosa, E. Raveretiana, E. Bancrofti E. redunca var. elata, and E. salmonophloia. I have briefly referred to these swellings in E. redunca var. elata at pp. 94, 95, Part XXXIV of the present work.

“Swellings and knobs are frequently largest just where it springs from the ground.” See A. W. Howitt's remarks concerning E. polyanthemos at Part XLII, p. 59, of the present work.

It may be observed that all the above species have smooth or almost smooth barks.

In many cases the butt of E. coriacea forms a huge protuberance at the ground level, taking on a peculiar plastic appearance often seen in the coast districts in E. maculata (Spotted Gum) and Angophora lanceolata (Smooth-barked Apple). In E. coriacea, from this protuberance there spring out as many as four (and even more) stems of equal diameter, such stems being equidistant from each other, or nearly so.

N.—Abortive Branches (Prickly Stems).

The presence of abortive branches in Eucalyptus is very common. It is often noticed by rubbing one's hand down a stem when one feels the friction of short sharp prickles. Sometimes these are more or less concealed by the fibrous bark; in the case of Gums they may be quite evident to the eye.

I have been in touch for some years with Mr. Harry Hopkins, of Bairnsdale, Victoria, in regard to this phenomenon, in the beginning in regard to E. Consideniana, and I obtained the following useful note (which incidentally deals with other matters) through him:—

Mr. W. H. Harvey, Yarram Yarram, Victoria, who calls this tree “Prickly Messmate,” obligingly gives me the following information concerning its occurrence in that State. “It is very scarce, is only found in small belts, chiefly in the parishes of Willung and Carrajung. The tree thrives best and creates a fine barrel or bole in volcanic soils or chocolate loams, when it attains a height of about 50 feet in barrel, and up to 3 feet in diameter. Called `Prickly Messmate,' on account of the surface of the sapwood being covered as a rule with spikes or prickles. Has a yellowish-brown fibrous bark, and the surface is smoother

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(less prickly to the touch) than either Stringybark or Messmate. Wood-buff colour, fairly free from gum-veins, and very durable. Mr. J. Wills, Chief Clerk of Works, Alberton Shire, speaks very highly of this timber, and says that it gives as good results as any timber in the district.” (Journ. Roy. Soc. N.S.W., li, 448, 1917.)

Mr. Hopkins writes:—

But I may state that during several years experience at “bush work” in my younger days, I not infrequently came upon this feature, in both young and old trees of several species, but perhaps mostly in Gippsland in Red Gum (E. tereticornis), and to a lesser extent in Stringybark (E. eugenioides) and Messmate (E. obliqua). I have also seen it in Peppermint (E. radiata), Apple Box (E. Stuartiana), and E. rubida. There is no Consideniana in the district where I then was. Generally—I think always, in my experience—the trees showing the characteristic grew upon “wet” ground, with a clay retentive subsoil near the surface, though not actually swampy. In some trees—particularly in the Red Gum—these prickles extended through all the concentric layers of wood, from the outside to almost or quite the centre—in cases where the prickles were largely and well developed, and in some cases, more particularly the Peppermint and Stringbark, the prickles were much smaller, though perhaps very numerous, and appeared to have developed in the outer layers of the wood. In some cases I have seen the surface of the sapwood so closely covered with fine or small prickles that it might be described as articulate or papillous. This condition is certainly not confined to E. Consideniana. It may, I think, be found in any species of the Eucalyptus where the causes that produce it are present.

Mr. W. F. Blakely says they are very common in the Orange district, New South Wales, in E. hemiphloia var. albens, where they are known as “pimples.” I have seen them in a number of other species, but regret I have not made a list of them and of their prevalence.

Mr. C. E. Lane-Poole, speaking of E. Todtiana (the coastal Blackbutt of Western Australia) says it is disregarded by the housewife for firewood on account of its many prickles.

E. Planchoniana is sometimes known as “Needle Bark,” because it is prickly to rub down with the hand. The name “Porcupine Stringybark” is also applied to it for the same reason.

These prickles, which will probably be found in most species, if looked for, will be illustrated by photographs if specimens in E. Muelleriana and E. tereticornis, as supplied by Mr. Hopkins.

O.—Pendulous Branches.

It is very difficult to group species according to habit. Besides the question of size, there is that of length of branches, and of canopy. Most species are rather erect in habit, but some, of which E. sepulcralis F.v.M., of South Western Australia, is an extreme form, have pendulous branches, and we have all stages between the two. In this species the branches are intensely glaucous and so very drooping and extremely pendulous that it is known locally as “Weeping Gum,” and Mueller has suggested its cultivation in cemeteries.

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In this and the following species the branches are so elongated, thin, and pendulous, as to droop in an almost vertical manner. E. macrorrhyncha F.v.M., a Stringybark of inland eastern Australia; E. sideroxylon A. Cunn., an Ironbark of much the same range; E. Mitchelliana Cambage, of Mount Buffalo has much the same habit; E. acaciaeformis var. linearis, a so-called Peppermint of New England, has also markedly drooping branches. E. coriacea sometimes has branches so pendulous as to be known as Weeping Gum.

P.—Vertical Growth of Trees.

This subject is touched upon in Part XLVI, p. 123, of my “Forest Flora of New South Wales,” based on a paper by Mr. R. H. Cambage in “The Surveyor” (the official organ of the Institute of Surveyors of New South Wales) for 31st December, 1904, and 28th February, 1905.

A further paper from Mr. Cambage's pen will be found in Journ. Roy. Soc. N.S.W., lii, 377, and Eucalyptus parviflora is used illustratively. An abstract of this will be found in “The Australian Forestry Journal” for November, 1919, p. 353.

The subject is interesting to many people, because living Eucalypts are often used as corner or other posts in fencing, and if as growth proceeded the rails mortised into the tree were carried up and two panels of fencing injured, it is probable that living trees would cease to be used for the purpose, and would be destroyed forthwith. Mr. Cambage's experiments bear out the observations of people interested in fencing, that the mortise-holes remain at the same height from the ground as when they were made.