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CCXXXII. E. hybrida Maiden.

In Journ. Roy. Soc. N.S.W., xlvii, 85 (1913).

FOLLOWING is the original description:—

Arbor erecta, altitudine circiter 50 pedes. Cortex cinerea, laevis, corrugata. Lignum pallidum durum. Folia matura lanceolata vel late lanceolata, pallida virentia, tenuiora, circiter 8–12 cm. longa, vena peripherica margini approximata, venis lateralibus patentibus. Flores in breve panicula corymbosa, quaque plerumque 3–6 flora. Calycis tubus conoideus. Operculum acuminatum, calcis tubo aequilongum. Fructus cylindrico-conoidei, circiter 6 mm. lati, in orificium leniter contracti, margine tenui. Valvarum apices plusve minusve depressi, orificium rare tangentes.

An erect tree of about 50 feet high, the tips of the branches smooth, the butt with a sub-fibrous (peppermint-like) or flaky-fibrous and more or less flat-corrugated bark, greyish or blackish externally, hence some trees have been described as “Black Box.”

Timber pale-coloured, hard, interlocked, and probably valuable.

Juvenile foliage not seen in the strictly opposite state, but as seen, not different from the mature foliage except in width.

Mature foliage.—Lanceolate or broadly lanceolate, slightly falcate, acuminate, commonly 8 to 12 cm. long. Dull green, the same colour on both sides, rather thin and tough, lateral veins spreading, fine, the intramarginal vein not far removed from the edge of the leaf, oil dots not numerous.

Flowers.—Peduncles of moderate length, angular, usually in a short corymbose panicle, each with about three to six or sometimes more flowers. Calyx-tube conoid, 5 cm. diameter, often angular, tapering into a short pedicel. Operculum pointed and as long as the calyx-tube. Stamens inflected in the bud, anthers, small, yellow, opening in small slits near the top, filaments at base, and small gland at back, indubitably showing intermediate characters between the anthers of E. paniculata and E. hemiphloia.

Fruit.—When immature cylindrical, with a rim round the orifice; when ripe cylindrical to almost conoid, about 6 mm. in diameter, hardly constricted at the orifice, rim thin, tips of valves more or less sunk and rarely flush with the orifice.

Range.

Type from Concord, Sydney, N.S.W. (Rev. Dr. Woolls, 1890; R. H. Cambage, 10th February, 1901). It was originally found in Bray's Paddock, Concord, near Sydney, where I knew of six trees until recently, but building operations may soon exterminate these particular specimens.

Dr. J. B. Cleland has drawn my attention to a tree on Milson Island, Hawkesbury River (a short distance west of the Railway Bridge), which appears to be identical with that from Concord. E. paniculata Sm. is common on the island, but there is no E. hemiphloia. This suggests that the hybrid originated elsewhere than on Milson Island.




  ― 49 ―

Affinities.

The affinities of this species are almost intermediate between E. paniculata Sm., the Grey Ironbark, and E. hemiphloia F.v.M., the Grey Box.

This is the first species of this genus which has been named with especial reference to its hybrid character. I have a large number of instances of apparently indubitable hybrids. In most cases a pictorial illustration is necessary to make the hybridism clear, and I propose to describe them in this work when dealing with hybridism as a special subject.

Following is the first passage referring to this particular tree. The Cabramatta tree is the plant afterwards described as E. Boormani Deane and Maiden (see Part X, p. 330 of the present work). Its affinity is with E. siderophloia Benth. rather than with E. paniculata Sm. The Ironbark in Mr. Bray's paddock at Concord is E. hybrida.

The Ironbark group (Schizophloiæ) is less liable to variation in the nature of its bark than any of the preceding sections; and yet in some forms of E. paniculata the bark is less rough and deeply furrowed than in its allies, whilst in exceptional cases, when it goes under the popular names of “Ironbark Box” and “Bastard Ironbark,” the wood and fruit are those of Ironbark, but the bark less rugged. Some years ago, when the late Mr. Thomas Shepherd was residing with Mr. Bell, at Cabramatta, he called my attention to a tree which, so far as its general characters were concerned, appeared to be an Ironbark, the shape of the buds, flowers and fruit being similar to those of E. paniculata, and the wood being, in the opinion of the workmen, like the ordinary Ironbark of the neighbourhood. Mr. Shepherd called the tree “Black Box” and “Ironbark Box,” and entertained an idea that it might be an undescribed species. Although I have had specimens of this tree for some years, it is only of late that I have come to the conclusion that the tree in question is really an Ironbark, for on Mr. H. Bray's property at Concord a similar one has been pointed out to me. This the workmen called “Bastard Ironbark,” as the wood resembles that of Ironbark, whilst the bark is not furrowed as Ironbarks usually are, but is more like that of Box or Woollybutt. Having examined the fruit and leaves of this tree, and having ascertained that the wood is similar to that of Ironbark, I am now convinced that the tree which puzzled Mr. T. Shepherd and that growing in Mr. Bray's paddock are identical, both of them being varieties of E. paniculata. If hybridisation were possible in the genus, one would think that the “Ironbark Box” is a cross between Ironbark and Box, but according to the opinion of the late eminent naturalist W. S. Macleay, F.L.S., the impregnation of the flowers takes place before the operculum falls off, and hence in such a case crossing cannot be effected. As this matter has never been carefully investigated by any observer, nothing like certainty can be affirmed of the probability or improbability of hybridisation. (Rev. Dr. W. Woolls in Proc. Linn. Soc. N.S.W., xvi, 60–61, 1891.)

Ten years later Mr. Henry Deane and I drew attention to a Eucalypt which we had received from Mr. R. H. Cambage, and which we thought presented an instance of hybridism. This was the identical tree from Mr. Bray's paddock at Concord.

We are indebted to specimens of a species from Concord from Mr. R. H. Cambage, and the examination of the specimens from the point of view of hybridisation is so instructive that we relate it in detail. Mr. Cambage stated that his tree was growing among E. paniculata Sm. (another of the Ironbarks), with E. hemiphloia near. He added: “The fruits look like those of E. paniculata, but the bark is not that of an Ironbark. The bark is as smooth as that of E. hemiphloia, and continues right up among the branches.” Reference to the herbarium of the late Dr. Woolls showed that he had, many years previously, obtained specimens from the same locality, and following is a copy of his label: “E. paniculata, Bastard Ironbark. Bark something like Woolly Butt or Box.” The immature fruits have rims which remind one


  ― 50 ―
of those of E. melliodora, and while seized of its affinities to E. paniculata, E. siderophloia and E. hemiphloia, there was certainly evidence to look upon it as an aberrant form of E. melliodora and also of Bosistoana, an affinity which (as regards the latter species) had already been arrived at by Mueller (though in a different way) as regards the Cabramatta specimens. The fruits are a shade smaller than those of some specimens in our possession, and we have from time to time looked upon the tree as a possible hybrid between E. paniculata and E. hemiphloia, and E. paniculata and E. melliodora respectively. We have examined the trees referred to by Dr. Woolls and Mr. Cambage, and are of opinion that, while they may be properly described as “Black Box” and “Ironbark Box,” there are certain points of difference between them and the Cabramatta trees (E. Boormani) which make us hesitate in referring them to the same species. The foliage and fruits are less coarse than those of Cabramatta, and this circumstance, coupled with the fact that the trees grow amongst E. paniculata, may cause some observers who may be inclined to look upon the Concord trees as hybrids to consider that E. paniculata is one of the parents. Bearing in mind that cases of hybridisation amongst Eucalypts usually break down under fuller examination, we hesitate to believe that we have a case of hybridisation here, and will revert to the subject at some future time.

Four years later I stated that I had no doubt as to its hybrid nature. I had had the tree under observation in the meantime, and was of opinion that it was a form sufficiently distinct to receive a name.

E. paniculata Sm. × hemiphloia F.v.M. In these Proceedings (1901, p. 340) Mr. Deane and I referred, though with some doubt, to a “Black Box” or “Ironbark Box” from Concord, near Sydney. I desire to say that, having kept these trees under observation, I have no doubt as to their being hybrids of the species named. (Proc. Linn. Soc. N.S.W., xxx, 498, 1905.)

Eight years later still, I described the tree under the name E. hybrida.

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