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CCLXXXI. E. Houseana (W. V. Fitzgerald) Maiden.

In Journ. Royal Society, N.S.W., xlix, 319 (1915).

FOLLOWING is the original description:—

Arbor alta, altitudinem 80 feet attinens, aetate opposito-foliata florescens. Folia juvenia fere amplexicaulia, petiolis brevibus vel absentibus, latissime lanceolata ad fere ovata, basi cordata, apice obtusa, pallida saepa glauca, 8–12 cm. longa, 6–7 cm. lata. Venae patentes, venis principis fere parallelibus, margine crassata. Folia matura petiolata, alternata, falcata, petiolis 2 cm. longis, foliis ad 16 cm. longis et 4 cm. latis. Alabastri, pedunculis brevibus leniter planis, floribus sessilibus vel fere sessilibus, 4–7 capitulo. Operculum hemisphaericum circiter dimido cupula subangulare aequilongum. Antherae aperintes in fissuris parallelibus, versatiles, dorso glandula magna. Fructus non vidimus.

“Amongst the tallest of the tropical species, occasionally reaching a height of 80 feet.”

Particulars as to habit, bark, and timber, not available.

[The following is supplementary information from Mr. Fitzgerald's MSS. “Height 40–70 feet, trunk to 30 feet, diameter 1½–2½ feet, bark persistent, white to greyish-white, smooth; timber reddish, not very hard or tough.—Quoted by Maiden in Journ. Roy. Soc. N.S.W., li, 450, 1917.]

Juvenile leaves.—The following description has been drawn up from specimens in the flowering (or rather plump bud) stage; they represent, as far as we have them at present, the juvenile leaf stage; at the same time, they are mature to the extent that they are contemporaneous with the inflorescence. Opposite, almost stem-clasping, the petioles being very short or absent; very broadly lanceolate to nearly ovate, cordate at the base, apex blunt pointed, margin sometimes undulate, pale coloured, or entirely glabrous. Length 8–12 cm., width 6–7 cm.

Venation spreading, the principal veins roughly parallel, and making an angle of approximately 60 degrees with the midrib; the margin thickened, the intramarginal vein well removed from the edge, the venation distinct, particularly on the lower surface.

[From additional material collected by Mr. Fitzgerald, the following additions to the description have been drawn up:—

Juvenile leaves.—Slightly glaucous, equally green on both sides, slightly stem-clasping around a nearly terete branchlet, oval to ovoid or broadly-lanceolate, tapering into a blunt or rounded apex, up to 18 cm. (say 7 in.) long by 8 cm. (say 3? in.) broad, secondary veins roughly parallel, at an angle of about 60 degrees with the midrib and with abundance of fine anastomosing veins, the intramarginal vein well removed from the edge.—Maiden in Journ. Roy. Soc. N.S.W., li, 450, 1917.]

Mature leaves.—(Petiolate, alternate, lanceolate, falcate, with petioles of 2 cm., and leaves up to 16 cm. long and 4 cm. wide. Venation distinct, the foliage pale-coloured and glabrous and the two surfaces scarcely to be distinguished from each other.)




  ― 292 ―

Flowers.—Buds with short, slightly flattened peduncles, the individual flowers sessile or almost so, four to seven in the head as seen. Opercula hemispherical, about half the length of the calyx-tube, which tapers only slightly, and which is usually sub-angular. (Filaments turn red on drying. Anthers open in parallel slits, attachment of filaments versatile, large gland at back.)

Fruits not seen.

[Fruits conoid to hemispherical, small (rather more than 5 mm. in diameter), nearly sessile, the short broad pedicel continued into the calyx-tube, forming two or more angles. Peduncle of 5 to 7 mm., also flattish and angular. The fruit with a narrow rim, the tips of the capsule slightly exsert and not adnate to the edge. Description drawn up from material collected by Mr. J. H. Niemann at Pine Creek, Northern Territory, and given by me in Journ. Roy. Soc. N.S.W. li, 450, 1917.]

Type.—Isdell River near Mount Barnett Homestead, Kimberleys, North Western Australia, No. 1014, collected by W. V. Fitzgerald, May, 1905.

The sentences in round brackets ( ) have been drawn up from specimens (No. 1357) collected at the base of the Artesian Range, Kimberleys, by Mr. Fitzgerald. The sentences in square brackets [ ] have been drawn up from the sources stated.

In the following year (viz., 1916) Mr. Fitzgerald, on the eve of his departure for the war, placed certain of his botanical manuscripts in my care, and I found the following description of this species amongst them, which supplements, to some extent, my original description:—

Arborescent, branchlets angular; leaves on the young plants opposite or sub-opposite, shortly petiolate, ovate-cordate, obtuse, those on the tree alternate, conspicuously petiolate, broad to narrow-lanceolate, usually falcate, acuminate, all thin, of dull lustre, the oil dots copious, veins fine, numerous, ascending and evident, reticulated between, intramarginal one adjacent to the edge; flowers 4–8, sessile and rather closely packed, on axillary and lateral thick terete peduncles which are much dilated upwards; calyx-tube obconical, not ribbed; lid depressed, hemispherical, much shorter than the calyx-tube; stamens inflected in the bud; anthers oblong, with parallel distinct cells dehiscing longitudinally; ovary flat topped; style short.

Leaves (Juvenile) 3–4 inches long, (Mature) 6–8 inches long, the petioles to 1 inch. Peduncles 2 lines long; calyx-tube 2 lines or less in length. Stamens 2 lines, the filaments white.

Fruit not seen.

Locality.—On grassy plains, Upper Isdell River, base of Artesian Range (W.V.F.). The species is named in honour of Dr. F. M. House of Western Australia.

Affinity.—E. fœcunda, Schauer.

Range.

It is a tropical species occurring both in Western Australia and the Northern Territory.

Western Australia.—The type comes from Mount Barnett Homestead, Kimberleys, North West Australia (W. V. Fitzgerald, No. 1,014)—“In swampy and wet sandy localities, associated with the coarser kind of grasses were E. Houseana and E. ptychocarpa.” (Fitzgerald in “Kimberley Report,” p. 12).




  ― 293 ―

Appendix.—The name Houseana was used by Mr. Fitzgerald in the Western Mail, Perth, W.A., of 2nd June, 1906. No description of the plant was ever published. A small scale photograph was accompanied by the following words:—“Eucalyptus Houseana W.V.F., after Dr. F. M. House, is among the tallest of the tropical, species, it occasionally reaching a height of 80 feet. This tree usually occurs on well-grassed plains between the Isdell and Charnley Rivers (original description, p. 322).”

Northern Territory.—I attribute the following four specimens to this species:—

1. Scientific Expedition of Prof. (now Sir) W. Baldwin Spencer (and others) from Darwin to the Roper River, Gulf of Carpentaria, July-August, 1911. At Cullen Creek Prof. Spencer collected a specimen with glaucous foliage, twigs and buds. Leaves sessile but hardly stem-clasping; flowering while the leaves are still opposite. The leaves as much as 15 cm. long and half as broad.

Then I have three specimens from the Pine Creek Railway, viz.:—

2. Collected by Dr. H. I. Jensen, Government Geologist, Darwin, in August, 1913. His label reads, “Sessile leaf, white bark (? smooth bark—J.H.M.), small flower and fruit (no fruit available—J.H.M.), rather crooked branches.” Close to type.

3. A similar specimen from E. J. Dunn, Pine Creek Railway, same date, also in bud and leaf.

4. Specimen in leaf, bud, and flower from Pine Creek, J. H. Niemann, August 1904. This differs from the type, and Nos. 2 and 3, in having distinct pedicels to the flowers. There is a slight umbo to the operculum, probably because the bud is fully developed. The leaves are mostly narrower-lanceolate than the type, and most have distinct, though very short, petioles. (Original description, p. 320).

In Ewart and Davies' “Flora of the Northern Territory,” p. 311 (1917), I quoted the following additional localities:—

381. Burrundie (McKinlay River flats).

359. “Snow-white bark, smooth-barked tree, growing singly or in branches like Mallee. Medium size. It is crooked on poor soil, straighter on Burrundie alluvial soil.” Burrundie.

345. “Particularly partial to flooded clay flats. Like many trees it loses its leaves in the dry season.” Pine Creek.

379. “Tree up to 40 feet high, smooth white bark.” On flats, Pine Creek to Wandi.

375. Wandi. Non-glaucous.

380. Mount Diamond to Wandi Flats.

413. Umbrawarra.

Dr. Jensen says that the forms from the hills and from the flats may look very different, which may be due to a stunting of the former, which have a much smaller leaf and fruit.




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Affinities.

This is another of the few species which flower in the opposite-leaved or juvenile stage (See Journ. Roy. Soc. N.S.W., xlviii, 424 (1914)). If described from the type only, it might have been looked upon as homoblastic species, but the additional material I have quoted shows that, like E. praecox (loc. cit.), it is heteroblastic, like the vast majority of species of this genus. We can only say that it is an example of retarded heteroblasty.

Other instances of retarded heteroblasty in Eucalyptus are:—

E. Risdoni Hook. f. See Plate 32 of the present work.

E. Gillii Maiden. See Plate 67, op. cit.

E. cinerea, F.v.M. See Plate 89, op. cit.

E. cinerea F.v.M., var. multiflora. Plate 90, op. cit.

E. melanophloia F.v.M.

In the absence of a complete suite of specimens and full data as regards E. Houseana, I am only able to suggest relationships to the following species at present:—

1. With E. alba Reinw.

The flower-buds of E. Houseana may resemble those of E. alba a good deal. Exceptionally the leaf-blade may resemble that of E. Houseana in shape and venation, but that of E. alba is not sessile at any stage, not cordate at the base, and is often gross in size. Speaking generally, the foliage of E. alba is not pale-coloured, whether arising from glaucousness or not. Both species flourish in moist, low-lying localities.

2. With E. clavigera A. Cunn.

It differs from this species in the hairiness of the leaves (particularly) in young specimens, so common in E. clavigera, in the numerous flowers, in the great length of the peduncles and pedicels, and in the clavate shape of the buds of E. clavigera. The shape of the leaves and the venation may, exceptionally, be a good deal similar in the two species. (Original description, p. 321.)

3. With E. fœcunda Schauer, according to Mr. Fitzgerald himself.

E. fœcunda is figured and described in Part IV. I am not able to indicate close affinities, and leave the matter for further enquiry.

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