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No. 144: Eucalyptus siderophloia,


The Broad-leaved Ironbark.

(Family MYRTACEÆ.)

Botanical Description.

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

Botanical Description.

— Species, E. siderophloia, Benth. in B.Fl. iii, 220 (1866), where it is describedas follows:—

A tall tree, with a hard, persistent, rough and furrowed bark (F. Mueller and others).

Leaves ovate-lanceolate or lanceolate, much acuminate, straight or more frequently falcate, about 3 to 6 inches long, often rather thick, with numerous fine diverging veins, the intramarginal one close to the edge.

Peduncles axillary, or in terminal corymbose panicles, more or less angular, each with about 6 to 12 flowers, on distinct angular pedicels.

Calyx-tube shortly turbinate, about 2 lines diameter.

Operculum conical or acuminate, rather longer than the calyx-tube in the ordinary form.

Stamens 2 to 3 lines long, all perfect, inflected in the bud; anthers very small and nearly globular, the cells very short, opening at first in oblong slits, extending at length to the base or sometimes almost confluent.

Ovary convex or conical in the centre.

Fruit globular-truncate or obovoid, 3 to 4 lines diameter, not at all or scarcely contracted at the orifice, the rim slightly prominent, the capsule not much or sometimes scarcely sunk, the valves often protruding.

A "coarse" species, that is to say, having coarse fruits (as compared with the other Ironbarks, paniculata and crebra) and coarsely furrowed bark. Altogether a very sturdy tree, reminding one, in this respect, of the British Oak.

There is a glaucous form (var. glauca, Deane and Maiden)note which goes under the name of "Blue-leaf Ironbark" and "Broad-leaf Ironbark" in the Dubbo district.

Botanical Name.

— Eucalyptus, already explained (see Part II, p. 34); siderophloia, from two Greek words, sideros, iron, and phloia, bark, in reference to the common Australian name for such trees.

Vernacular Names.

— "Broad-leaved Ironbark." Perhaps this is the most distinctive name for this species, a characteristic by which it may be readily distinguished, particularly in young trees. It is often called "Red Ironbark," particularly from northern localities.

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We have fournote principal Ironbarks, three of them of especial value. Timbers of this class are so important that it will be interesting to discriminate them. There is a good deal of confusion in regard to the local names given to Ironbarks, and the names I suggest for the four species seem to me the least objectionable. At the same time the names "Narrow-leaved Ironbark" and "Broad-leaved Ironbark" are too cumbersome for ordinary use, and certainly for persons outside the State. It is probable that Ironbark for the export trade will go forward under two names only, viz., Grey Ironbark and Red Ironbark, the first being the white or grey 1ronbark, and the second including both the "narrow and broad-leaved Ironbarks," the timbers of which closely resemble each other. The fourth Ironbark, whose botanical name is Eucalyptus sideroxylon, is mainly an interior species, and will seldom, if ever, be exported. Perhaps timber will go forward under the single generic name of Ironbark; if so, I wish to impress on friends at a distance that our various species of Ironbark vary a good deal in colour, as a consignee may readily be confused if an Ironbark be sent to him different in appearance to that to which he has been accustomed. Because of the great importance of Ironbark, I proceed to deal with these timbers with a little more detail than with the other hardwoods.

Table of Ironbarks. — The following table brings out the principal points in Ironbark trees and Ironbark timbers, and may help to elucidate them:—

White or She Ironbark (paniculata).  Narrow-leaved Ironbark (crebra).  Broad-leaved Ironbark (siderophloia).  Red Ironbark (sideroxylon). 
Colour (darkens with age.)  Very pale; pink when fresh.  Medium red   Medium. A little darker than preceding.  Very dark. 
Strength of timber  Best. OFten pale coloured, even grey. Furrows often anatomosing.  Good. Very deeply furrowed, inferior in depth only (if at all) to sideroxylon.  Good. Often of a flaky character.  Inferior. Dark; deepest furrowed. 
Leaves  Narrow and medium.  Very Narrow.  Very broad.  Medium; foliage often sparse. 
Flowers.  White.  White.  White.  Crimson; sometimes creamy. 
Fruits.  Small.  Very small.  Rather large.  Large. 

Aboriginal Names.

— "Derrobarry" is the name given by the Sydney blacks according to George Caley, who collected for Sir Joseph Banks, 1800 — 1810. Later on (1854), the late Sir William Macarthur gave the name as " Terri-barri, " evidently the same name. " Algerega " of the Clarence River aborigines.

It is said to have been called " Tanderoo " by the natives of Southern Queensland.

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— E. fibrosa, F.v.M., and E. ornata, Sieb. (See Crit. Rev. gen. Euc., Part x, p. 325.)


— The coarseness of the foliage in this species has already been alluded to.

Flowers. — The buds are often, when young, of the "egg-in-egg-cup" shape — that is to say, the operculum is of noticeably less diameter than the calyx. (See figure.)

The bud is commonly beaked, but it is a mistake to say that there is a beaked (rostrate) form of the species. This is dealt with at p. 324, Part x, of my Critical Revision of the genus Eucalyptus.


— The fruits have generally exsert valves (teeth, some people call them), which is usually quite sufficient to distinguish this from other Ironbarks. (See figures D and E of Plate 148.)


— The ridges of bark common to all Ironbarks are flattest in this species, that is to say, in other Ironbarks they are sharper and more conical in section.


How to tell Ironbark. — It is not very easy in a few words to give a definition of Ironbark. Of course, if the bark is available, the thing is simple enough, for most of the barks are characteristically furrowed and rugged. To describe it we must take note of a variety of circumstances. It is heavy (almost the heaviest of our hardwoods). It is hard, as may readily seen if it be touched with a plane, or a nail be driven (or attempted to be driven) into it. Its most characteristic property, however, is a certain "gumminess" in working, which is well brought out under the plane, and its horny texture. The result is that, when planed, ironbark shows the appearance of more or less parallel striæ or lines of close-textured wood, strongly resembling horn, while between these the wood has a more open grain, showing narrow pits which may be seen, even by the naked eye, to be filled by a substance of resinous texture. In some specimens it is not easy, however, to make out these lines of horny-textured wood, but the resin-pits appear to be always present. Ironbark is more or less curly in the grain, consequently it often gives trouble to plane to a perfectly smooth surface. If a blunt tool be used, the ironbark tears in fairly regular blotches, while to get a perfectly smooth surface the wood often requires to be traversed with the plane, or even to be gone over with the steel scraper. Its hardness and weight often precludes it from use-perhaps an advantage, as otherwise the consumption of this timber would be inordinate.

A rough-and-ready method (and in the hands of an expert a satisfactory method) of testing whether a timber is Ironbark, is to cut a fragment — say 2 or 3 inches long, and only as thin as a piece of twine-with a penknife; its tensile strength is tested between the fingers.

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Principal Uses. — Ironbark is the king of New South Wales hardwoods — in fact, it is not excelled in any part of the continent for combined strength and durability. It is extensively used in bridge-construction, for railway sleepers, for posts, for naves, spokes, shafts, and framing by the waggon and carriage-builder; for large beams in buildings, particularly in stores for heavy goods-in a word, wherever great strength is required. For such purposes as railway sleepers it will last an indefinite period, and in many cases has to be taken up, not because it shows signs of decay from exposure on the permanent-way, or disintegrating because of the vibration to which it has been subjected, but because holes have been made in the sleeper by the renewal of bolts and spikes. I have seen specimens of sleepers which have borne the heaviest traffic of the main line near Sydney for twenty-five years, and which are as sound as the day they were laid.

Coming to the particular Ironbark of which we are speaking, the timber has the highest reputation for strength and durability, and is used for largebeams in stores for heavy goods, railway sleepers, and other purposes where great strength is required. It is also used for dray poles. Its extreme hardness renders it difficult to work. It is largely used for spokes.

Following are specimens of this timber in the Technological Museum, interesting because of the notes in regard to them. Notes half a century old and more in regard to Ironbarks which can be botanically determined now, are rare. (1) No. 4, London Cat., 1862; 137, Paris Cat., 1855. "Broad-leaved Rough Ironbark," and "Terri-barri," names in Cumberland and Camden. Diameter, 24 to 48 inches; height, 80 to 120 feet. "From Appin, common in Cumberland; one of the strongest and most durable of timbers." The Paris Cat. also states: "Roughleaved, rough-barked Ironbark." "This tree has been proposed as their emblem by the colonists of New South Wales." Of a very dark colour, very good to work, and even in grain. (2) "Ironbark of the Clarence" — "Algerega" of the aborigines. "This well-known tree attains a very large size in the northern districts-upwards of 100 feet in height, and as much as 5 feet in diameter. Timber very highly valued for its unequalled strength and durability; it is used for all kinds of fencing, shingles, beams, dray poles, plough beams, and various other purposes; when properly seasoned it will not shrink." (Cat. London Exh., 1862.) It is of a darkbrown colour, heavy, hard, and close in the grain. (3) The wood described in the Sydney Mint Experiments, 1860, as "Rough-barked Ironbark, E. resinifera," is E. siderophloia. It came from Brisbane, and "is much prized for building and other purposes." Specific gravity, 1.15; value of E., 639,400; of S., 2,962. It has a wavy grain, and is of a dark, reddish-brown colour. It is tough, hard to work, and well adapted for the felloes of wheels of drays and carts of all sorts. It lasts well for piles in water, and for posts. It is very heavy.

The Ironbark of the Clarence is not liked as compared with southern Ironbark, as it is inclined to split and shell.

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Speaking of this Ironbark, chiefly from the Manning River district, the late Mr. Augustus Rudder wrote:

The mature trees are generally pipy, and the colour of the wood is red. The timber of this Ironbark is strong, hard, dense, and heavy, but in lasting quality is not always reliable, as I have repeatedly seen it quite rotten after ten or fifteen years, but this is not usual. It is very plentiful in places, in the Clarence River district in particular, but in these parts the timber is of inferior quality, especially on the ridges, where the trees are stunted and badly grown. For railway sleepers this timber is fairly good, but is scarcely to be recommended in the round, as a rule, for bridge-work, as its central heartwood is not reliable, and it is very subject to the white ant, more so than any other hardwood I know of.

At the mill-brook, in the town of Stroud, are the remains of the old bridge, erected, when we examined it in 1895, about fifty years previously. The foundations consisted of logs in the round laid crosswise over each other. Mr. de Coque and I went into the bed of the creek, and examined two of the lowest logs, which were moss-grown, and which had been. exposed on the ground, between wind and weather, for half a century. With the axe we took out chips, and the logs proved to be grey and red Ironbark, still perfectly sound, except where the water had got into the suncracks. It will be admitted that this is a good test of the durability of any timber.


— This is a large tree, attaining the height of 100 feet, with a diameter of 4 feet and more. Being a timber in such demand, most of the largest trees have long since been cut down in readily accessible places.


— It occurs from the Clyde Mountain in the south, along the coast ranges to North Queensland. Westward it is found as far as Wellington and Dubbo, also at Mudgee. With E. crebra it is found from Dubbo to the North-Westerin line.

I shall be glad if correspondents will send me specimens from as many southern and western (New South Wales) localities as possible. Mr. A. Murphy has collected it from Rockhampton, Queensland, and his specimens are precisely similar to the Sydney ones.


Plate No. 148: Broad Leaved Red Ironbark (Eucalyptus siderophloia, Benth.) Lithograph by Margaret Flockton.

  • A.,B. Sucker-leaves from Smithfield, near Parramatta.
  • C. Flowering twig.
  • D. Fruits from the same branch.
  • E. Fruits from Smithfield.
  • F. Larger buds of what was at one time known as var. rostrata, of this species, from Cabramatta, near Liverpool.
  • G. Anther.


A "Broad-leaved Ironbark " from Wyong. Girth 21 feet, and trunk 55 feet to first fork. Note the flat appearance of the ridges of the bark, which is characteristic of the species. — (F. A. Kirton, photo.)

Footnotes Issue No. 144.

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