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  ― 231 ―

CCLXXIV. E. decorticans sp. nov.

ARBOR magna, cortice nigricante dura sulcata, E. siderophloide similibus; ramis albis, laevibus, deciduis, ligno rubro mediocre; foliis junioribus angustissimis lineari-lanceolatis vel lanceolatis; foliis maturis lanceolatis utrimque aeque viridibus, venis (praeter costam mediam) inconspicuis; calycis tubo obconico in pedicellum brevem angustato; operculo plerumque obtuso; fructu ovoideo-cylindrico, 7 mm. diametro, valvarum apicibus paulo exsertis.

Bark.—On the butt blackish, hard, furrowed, with flattish ridges after the fashion of E. siderophloia but with bare branches as described by Dr. T. L. Bancroft in the following extract from a letter:—“A remarkably fine tree, like a large Grey Ironbark, but the branches of the top, up to the size of a man's arm or even thicker, are white in colour; covered with a thin, smooth bark; the bark is always peeling off these thin branches, and the ground below is strewn with it after the style of E. hemiphloia.”

Timber inferior in quality, colour red.

Juvenile leaves.—Extremely narrow, linear lanceolate to lanceolate, some specimens having an average length of 5 or 6 dm. and a diameter of 8 cm., oil dots abundant.

Mature leaves.—Lanceolate, slightly curved, acuminate, equally green on both sides, drying to a pale green, venation (except the midrib) inconspicuous, the lateral viens very fine and somewhat spreading, the marginal vein close to or very near the edge.

Flowers.—Umbels three to six flowered, usually three or four together in short axillary or terminal panicles, the peduncles angular. Calyx-tube obconical with one or two angles, tapering into a short pedicel. Operculum usually blunt-pointed, about as long as the calyx-tube. Stamens inflected in the bud, anthers broad, white, opening at the sides, filament at the base, small gland at the top.

Fruit.—Ovoid cylindrical, and 7 mm. in diameter, often with one or two angles, with a darker coloured rim hardly constructed at the orifice, the tips of the valves slightly protruding.

This form is known as “Mountain Ironbark,” “Naked Top Ironbark,” or “Gum Top.”

This description is based on one in Journ. Roy. Soc. N.S.W., xlvii, 80 (1913), but we have acquired additional information concerning it, and it now seems distinct, and therefore a name should be given to it. I have therefore pleasure in bringing Mr. F. M. Bailey's forma decorticans (of E. siderophloia) up to specific rank, if that be admissible. I take the opportunity (in addition to the name of Dr. Bancroft already quoted) of saying how indebted I am to Mr. C. T. White, the Government Botanist of Queensland, for valuable help.

Synonyms.

E. siderophloia Benth. forma decorticans Bailey, in Queensland Agric. Journ., xxvi, 127 (March, 1911).

“This tree resembles the narrow-leaved forms of the species (siderophloia), differing principally in the bark of the branches, even when as thick as a man's arm, being deciduous.” (Complete original description.)




  ― 232 ―

Range.

So far as we know at present it has only been received from the Burnett River district of Queensland. It was originally sent by Dr. T. L. Bancroft, its discoverer, from Eidsvold, where it occurs on rocky mountainous country, associated with E. siderophloia. Mr. Forest Guard S. J. Higgins (sent by Mr. C. T. White), collected it in the parish of Boondooma, but there is no doubt that, having been confused with other Ironbarks, it has an extensive range.

Affinities.

With E. drepanophylla F.v.M.

In Journ. Roy. Soc. N.S.W., xlvii, 80, I considered E. decorticans to be specifically identical with E. drepanophylla, but additional material has caused me to form a different opinion. Phylogenetically, E. drepanophylla may be looked upon as a coarse form of E. crebra, and most observers do not discriminate between those two species, many of the references to E. crebra including E. drepanophylla. It is possible that E. decorticans has, like E. drepanophylla, evolved from E. crebra. I attach great importance to Dr. Bancroft's observations. He says E. decorticans is a denizen of dry, rocky hillsides, while E. crebra grows on flatter country. E. decorticans has a deciduous bark on the branches, and a poor timber, differing from E. crebra in both these respects.

The anthers of E. decorticans are semi-terminal, or approaching the group provisionally termed Porantheroid; those of E. drepanophylla are small, opening in parallel slits, simulating those of E. crebra.

Partly because of the narrowness of the juvenile leaves (borne out, I may say, in the seedlings), I wrote to Dr. Bancroft about the relation of the new species (decorticans) to the widely diffused E. crebra. He replied: “I am absolutely certain that the sucker leaves are extremely narrow, more so a lot than those of E. crebra. The new species and E. crebra do not grow together.” In another letter he says that they are as narrow as those of E. Seeana Maiden. See fig. 1a, Plate 132, Part xxxii, of the present work.

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