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No. 52: Eucalyptus sideroxylon,

A. Cunn.

The Mugga; a Red Ironbark.

(Natural Order MYRTACEÆ.)

Botanical description.

— Genus Eucalyptus. (See p. 33, Part II).

Botanical description.

— Species Eucalyptus sideroxylon, A. Cunn.

Following is the earliest record I can find of this species:—

At the base of the range of hills at Mount Maude some tolerable fair specimens of the Western Ironbark, Eucalyptus sideroxylon, were noticed, being easily distinguished from its congeners by its extreme rugged, furrowed bark, containing, like others of the Eucalypti, a strong astringent gum. — (A. Cunningham's MS. Journal, under date 19th May, 1817)

Oxley's Expedition was then in latitude 33° 25' and longitude 147° 10', i.e., about midway between Condobolin and Wyalong West. Some of these specimens were distributed with Cunningham's name.

The next reference I can find is:—

6th October, 1846 (near Mount Pluto) . . . . . and among the larger forest trees was a Eucalyptus, allied to, but probably distinct from, the E. sideroxylon, A. Cunn., p. 339. — (Mitchell's Trop. Journ. Austral., 339.)

In the list of plants collected by Mitchell's Expedition, at p. 437 of his work, this plant, referred to at p. 339, is given as Eucalyptus sideroxylon without any qualification. I have seen the specimens in question, and they are what we know as Eucalyptus sideroxylon, A. Cunn.

Then Mueller described a species, under the name of Eucalyptus leucoxylon, in the following words:— "Arboreous:

Leaves. — Alternate, somewhat shining, narrow lanceolate, subfalcate, tapering into a long uncinate acumen, veined and furnished with pellucid dots; umbels axillary, generally three-flowered, with a thin peduncle.

Lid. — Conico-hemispherical, acuminate.

Tube of the calyx. — Semiovate, somewhat longer than the lid.

Fruits. — Semiovate, hardly contracted at the orifice; the valves of the capsule inclosed.

Seeds. — Blackish clathrate.

In grassy plains from the Avoca to St. Vincent's and Spencer's Gulf.

This is the "White Gum Tree" of the South Australian Colonists." — (Trans. Victorian Inst., i, 33 [1855]).

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Thereafter, for many years, this "White Gum" was confused with the New South Wales "Ironbark." For example, Bentham, in the Flora Australiensis (iii, 210), who is followed by Bailey, in the Queensland Flora. Then Mueller, in Eucalyptographia, continues to confuse the two trees. But in the field they could not be considered identical for an instant. Benthain's description of Eucalyptus leucoxylon applies very well to tbat of Eucalyptus sideroxylon, but requires to be supplemented in the following points:—

E. sideroxylon.  E. leucoxylon. 
Juvenile leaves  Linear-lanceolate or linear.  Cordate or ovate-lanceolate, sessile. 
Bark  Black, furrowed and rugged (Iron-bark)  Whitish or bluish, smooth (White or Blue Gum.) 
Timber  Deep red.  Pale brown or white (hence the name leucoxylon). 


— In B.Fl. iii, 210, Bentham has a variety minor (of Eucalyptus leucoxylon).

Flowers rather smaller and often more numerous at the ends of the branches. This variety seems almost to pass into melliodora.-Parrainatta (W. Woolls).

I have seen the original and it is Eucalyptus sideroxylon, with rather smaller flowers than the type. But inasmuch as the species varies much in the size of the flowers, some being even smaller than those of the so-called variety minor, it seems a pity to perpetuate it. The specimen is also called "variety rubriflora" on the label, but since the colour of the flowers of many individual trees of this species varies from year to year, this name is unfortunate also.

Variety pallens, Benth., of leucoxylon (B.Fl., iii. 210).

Leaves not so coriaceous and whitish.

This form is really an Ironbark, and therefore a variety of sideroxylon. For example, "Mountain Ironbark," Upper llunter (H. Deane) ; also head of Gwydir (Leichhardt). Sometimes this variety pallens has been labelled "Eucalyptus paniculata variety."

The following may be classed with the same variety, but they are too coriaceous to be typical. — "Silver-leaved Ironbark," New England (W. Woolls); "leaves very broadly lanceolate, whitish," Murrumbo (R. T. Baker). The collection of fruits of these may, however, show that these specimens really belong to sideropliloia, Benth., var: glauca, Deane and Maiden.

Botanical Name.

— Eucalyptus already explained (Part ii, p. 2J4) ; sideroxylon, from two Greek words — sideros (iron), xylon (wood) — in allusion to the hardness of the timber. It is an Ironbark, and the timber of the one now under review is one of the softest of the Ironbarks.

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Vernacular Names.

— Its aboriginal name is in very common use, and it is also known as "Red Ironbark" because of its timber, but the timbers of other Ironbarks (e g., siderophloia and crebra) are also red. For obvious reasons it is also called "Red-flowering Ironbark." Sometimes it is called "Black Ironbark," because of the darkness of its bark. A very common name is "Fat Cake," or "Fat-cake Ironbark," because of the pulverulent look of the bark, interspersed as it is with blackish kino grains, the general appearance reminding one of a burnt greasy cake.

The name "Mountain Ash," as applied to E. sideroxylon, has doubtless crept into the Flora Australiensis and other works on Oldfield's authority. Following is one of his labels, in his own handwriting:— Oldfield confused, as regards bark at least, Eucalyptus sideroxylon with the Mountain Ash (Eucalyptus Sieberiana), which in the south-east of New South Wales has bark like an Ironbark.

lronbark, or Black Mountain Ash of colonists; tree, 180 feet; bark persistent, brittle with dots of gum; bark, iron-grey, rough, with prominent ridges; wood very hard. Mountain Hut Range, near Eden, Twofold Bay. — (Herb. Barbey-Boissier.)

Oldfield added later, "Eucalyptus sideroxylon A.C.," with which determination I agree.


— Eucalyptus formosa, J. Backhouse, "No. 18, near Liverpool, New South Wales," in Herb. Calcutta, is Eucalyptus sideroxylon, A. Cunn. The confusion with Eucalyptus leucoxylon has already been referred to.

Juvenile Leaves.

— I desire to invite especial attention to the young foliage of this species, which is very different in shape from that of Eucalyptus leucoxylon, the species with which Eucalyptus sideroxylon is most commonly confused


— This is the New South Wales species of Eucalyptus which most frequently has red or rather pink or crimson flowers. Often, however, it has creamy white flowers.


— The shape will be noted from the figure. A point worthy of remark is that it has a round rim or ring round the mouth, as is often seen in the smaller fruit of the Yellow Box (melliodora). It also has warty excrescences such as are seen in Eucalyptus leucoxylon (from Victoria and South Australia), in Eucalyptus maculata (Spotted Gum), and a few others.


— The bark of this species has been referred to under "Vernacular Names." The ultimate branchlets are smooth, while those of Eucalyptus crebra (another Red Ironbark often associated with it) are rough.


— The wood of this is the deepest in colour, and also the softest and least valuable of the ironbarks. The tree is often pipy and gnarled, but in many places it is a fine timber tree. Where one of the other ironbarks is available, this ironbark suffers by comparison; nevertheless, it is a useful timber, and is employed

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in public works for such purposes as railway sleepers and posts, where long lengths are unnecessary. Frequently good lengths cannot be obtained, and if they could the tensile strength of this timber is not equal to that of the best ironbark.

This tree has a straight even bole; the timber is of the highest reputation for strength and durability, and is very much used for large beams in stores for heavy goods, poles for bullock drays, railway sleepers, girders and piles for bridges, and other purposes where great strength is required. It is one of the best fuel woods in New South Wales for domestic uses and steam-engines. Its average weight is from 75 to 78lb per cubic foot when green, and it loses 3 to 5lb. in drying within the first two years. — (General Report, Sydney International Exhibition, 1879) Colour of timber dark red. A most valuable and durable timber for all kinds of outdoor and strong work. It is extensively used for fencing and building, railway sleepers, girders, beams, joists, shafts of drays, and all descriptions of work where strength and durability are required. — (Forest Ranger Postlethwaite, of Grenfell.) Red Ironbark very plentiful all over the Mudgee district. Used for naves, spokes, shafts, and nearly every description of rough carpentry. The timber of this species growing in this district seems to be easier worked than similar trees growing elsewhere. — (Forest Ranger Marriott, Mudgee.)

Found about Harvey's Range, Dubbo, and a small patch on Hermitage Plains. Timber red and soft; soon wears. Not considered a good timber. Will not be taken for public works. Used for fencing. — (Forest Ranger Martin.) With reference to the statement about public works, it is inferior to Eucalyptus crebra, but Mr. Deane (Engineer-in-Chief for Railway Construction) told me he would use it for sleepers, as its durability is good. He informed me that he would judge each sleeper on its merits, no matter from what species of Ironbark it may have come.

The timber is used freely for railway sleepers, and althougb it is considered one of the finest woods of the west, it is not to be compared for general use with Eucalyptus panicalata, Sm , the Grey or White Ironbark of the coast. The wood of the latter tree is tough, while that of the Western one is comparatively dry and brittle. — (R. H. Cambage.)

A railway engineer informed Mr. J. V. de Coque that his experience of Mugga only gave the timber a six or seven years' life.

Mr. J. V. de Coque gives the following interesting, notes of Mugga and Ironbark (Eucalyptus crebra) in the Dubbo district, where both are abundant and associated:—

On entering a forest where the two timbers grow the Mugga shows first — seems to grow at its best on outskirts of timber belt. The two timbers, Mugga (sideroxylon) and Ironbark (crebra), are easily distinguished growing owing to the deep red colour of the Mugga bark and the gum crystals which are embedded throughout the bark. The Mugga seems to be the happy home of the big grub Eudoxyla, and from what I can learn from the saw-millers, they state that they rarely find any hole to denote the entrance of the insect. In sawing Mugga timber it rapidly clogs the teeth of the saw with a resinous substance. It is therefore objectionable to the sawyer. I cut two logs myself over the circular-saw bench. The ironbark piece cut clear, the Mugga even in so short a piece clogged the teeth.

The only timber I know which puts so much resinous matter on the saw is the Eucalyptus globulus of Victoria and Tasmania, which can only be cut to satisfaction with a spray of water constantly flowing between the teeth.

Eucalyptus sideroxylon is not a common tree in Victoria, hence the following unpublished notes by the late Mr. G. Perrin, Inspector of Forests, in 1898, are interesting:—

The Red Ironbark (Eucalyptus sideroxylon)note is next to Red Gum (Eucalyptus rostrata) in commercial importance, and, like the Red Gum, this tree has been shamefully misused in the past, and for this misuse the miner

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is responsible. It is a most valuable timber tree, and for manufacturing purposes is far more so than Red Gum; the texture or grain of the wood is not unlike that of Jarrah, but it is not interlocked, being more fissile or straight in the grain. The wood is clean, without knots, and singularly free from faults common to most eucalypts — gum-wells, veins, or dry rot.

A marked peculiarity of this tree is its preference for auriferous localities, as it is invariably found growing on the quartz ironstone ridges along the main leads of the more important gold-fields. The tree is a fast grower, and has a clean straight stein, with an average height of 40 feet.

Matured timber is now very scarce, and on the most of the gold-fields it has been cut out. Millions of young trees are taking the place of the old matured ones, and in a few years, with care and attention, large quantities of this valuable wood will be again available. The timber is suitable for wood blocks and carriage or coach building. It is a tree which should be specially protected by proclamation from cutting in its sapling state. Ten of thousands of young trees have been cut on all the mining centres for firewood for engine fires as well as household use.


— Its bark contains large quantities of kino, which also permeates the wood.

Mr. Forester Allan, writing to me, says:—

I obtained the gum from the ironbark by boiling the bark and straining the liquor, after which I reduced it to a thick consistency. Large quantities can be obtained by this process at little cost.

It will probably be found useful for tanning purposes.


— It attains a height of 100 feet and a diameter of 4 feet, though usually it is much smaller Foresters Postlethwaite, of Grenfell, and Marriott, of Dubbo, both quote the height as 100 feet, and the diameter as 2 feet. Forester Martin, formerly of Dubbo, gave the height as 40 to 60 feet, and the diameter as 18 inches to 3 feet.


— In New South Wales it occurs in the bush between Parramatta and Liverpool, in paddocks at South Creek, and in the neighbourhood of Richmond, and again beyond the Blue Mountains, near Mudgee and Wellington, and elsewhere, being widely diffused over the auriferous districts of the western and south-western interior. It is rare in the southern part of the State, becoming more plentiful on the ranges near Moruya; getting more plentiful further north. It is usually found on poor, sterile, ranges, and is usually unaccompanied (except in the Dubbo district) by any other species of ironbark.

The following more detailed notes are by Mr. R.H. Cambage:—

It is rarely found growing at an altitude exceeding 2,000 feet above sea-level. In going west it is first met with on the western line beyond Kerr's Creek, and on the Orange to Forbes line beyond Molong, so that it covers much the same country as Eucalyptus tereticornis, var. dealbata, and also prefers ridges. In the west this species bears a profusion of blossoms in the months of April and May. It is fairly plentiful between the Macquarie and Murrumbidgee Rivers, occurring in patches, and shows a decided preference for sedimentary formations. — (Proc. Linn. Soc., N.S.W., 1900, 715.)

This ironbark is commonest in the Central Division of New South Wales and its "curving boundary" to the west (as far as I know it) is a line roughly drawn through Germanton (near the Murray), Wagga Wagga, Hillston, Nymagee, Cobar, Dubbo, Narrabri, Warialda, Inverell, and thence to the Darling Downs, in Queensland. I shall be glad if correspondents will favour me with any localities west of this boundary.

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In spite of the reckless extravagance with which this timber has been cut, it is by no means scarce, especially in some localities, a few miles from the coast. While it is a very slow-growing tree, there is some consolation in the fact that it usually grows in barren, rocky country unsuitable for agriculture, and therefore wholesale clearings are not made as in the case with many other timbers. At the same time it does not readily reafforest.


Mr. A. W. Howitt says this is the only ironbark in Victoria although Eucalyptus leucoxylon (with its white bark and hard timber), is often known as White ironbark.

The chief localities for its growth are Bendigo, Maryborough, Dunolly, Moliagul, Inglewood, Bealiba, Heathcote, M'Ivor, and Chiltern, and several other places in small quantities; also in certain places in mining centres in Gippsland, Walhalla, and other places. — (G. Perrin.)


Darling Downs and the mountainous country adjoining New England (New South Wales.)

Explanation of Plate 49

Plate 49: The Mugga: A Red Ironbark (Eucalyptus sideroxylon, A.Cunn.)(G.H.K. are E. leucoxylon, F.v.M.) Lithograph by M. Flockton.

  • A. An original specimen in flower collected by Allan Cunningham.
  • B. Seedling raised from seed collected at Stuart Town, N.S.W.
  • C. Natural seedling from Condobolin, N.S.W.
  • D. Fruits from Condobolin Hill (whence the preceding seedling was obtained). Observe the warts frequently seen on the fruits of this species.
  • E. Fruits from Cootamundra to Grenfell.
  • F. Fruits from Cabramatta, near Sydney. All the above are E. Sideroxylon, A. Cunn.

The following are Eucalyptus leucoxylon, F.v.M., for comparison.

  • G. Seedling from seed obtained at Mount Lofty, S.A.
  • H. Pair of juvenile leaves from Kapunda, S.A.
  • K. Pair of juvenile leaves, a stage further advanced, from the same place.

Footnotes Issue No. 52

Supplementary Material Added at the End of Volume 2

No. 52. Part XIII.

Eucalyptus sideroxylon, A. Cunn.


(Natural Order MYRTACEÆ.)

Varieties. — See vol. ii, P. 66.

Under the above name I have discussed Bentham's variety pallens of E. leucoxylon.

I have raised this to a species under the name E. Caleyi.* It is a Red Ironbark, and much esteemed as a timber tree in the districts in which it grows.

It will be figured and fully described in due course.

Hybridisation. — E. sideroxylon is a species which readily hybridises, with the Boxes, at any rate. Some of the hybrids are so like E. sideroxylon that it is difficult to distinguish them unless the trees be seen or a complete suit of specimens, including juvenile foliage, be available. E. sideroxylon has narrow juvenile foliage, and hence is readily seen to be different from a number of broad-foliaged trees more or less related to it. I have dealt with the matter of hybridisation in Eucalypts, as far as this and other species are concerned, in Proc. Linn. Soc. N. S. W., 1905, p. 492.

Supplementary Material Added to Volume 3.

No. 52. Part XIII. Eucalyptus sideroxylon, A. Cunn. THE MUGGA; A RED IRONBARK. (Family MYRTACEAE.)

Aboriginal Names. - See vol. ii, p. 67. "Yehrip" is the Victorian aboriginal name for the Ironbark, according to Mr. J. G. Saxton.

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