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CCLXXXIV. E. pumila Cambage.

In Proc. Roy. Soc. N.S.W., lii, 453, 1918 (with Plate XXXVII).

FOLLOWING is the original description:—

Arbuscula alta, cum truncis multis separatis, in altum pedes quindecim viginitive extendens, trunci diametrum unciarum duarum triumve habens.

Ramusculi angulares præcipue ad extremitates.

Folia (reversio) tenera ovata ad ovata-lanceolata, 3–5 cm. longa 1–1·5 cm. lata.

Folia matura linearia-lanceolata ad ovata-lanceolata, modice crassa, sex ad duodecim cm. longa, unum ad tria cm. lata, sæpe leviter falcata; utrobique obtuse viridia, extremitates fuscæ et flaccide, systema venosa modice clara, venæ laterales angulis cir. circiter 40 ad 55° e corta media dispositæ, vena inter margines plerumque juxta marginem, olei glandulæ numerosæ. Petiolus 1–1·5 cm. longus.

Gemmae.—Fuscæ cum colore viridi tinctæ, proper sessiles vel cum pediculis circiter unum mm. longis, operculum conoide, quinque ad septem mm. longæ, calycistibus vix longitudinis dimidius pedunculus, aliquanto complanatus circiter unum mm. longus.

Flores.—Circiter septem ad tredecim in umbella, antheræ modicæ callæ parallelæ.

Fructus.—Prope sessiles, hemisphericales, diametrus circiter septem mm. plerumque cum quatuor valvis exsertis, ora crassa, convexi.

Cortex.—Tenuis et levis ad humum, interdum cum vittis pendulis longis, crassus ·5–2 mm., color cinereus vel subviridis.

Lignum.—Fuscum in centrum, durum.

A tall shrub of many separate stems reaching 15–20 feet high, with stem-diameter of 2–3 inches.

Branchlets.—Angular, especially towards the tips.

Juvenile (reversion) FOLIAGE.—Ovate to ovate-lanceolate, 3–5 cm. long, 1–2·5 cm. broad.

Mature leaves linear-lanceolate to ovate-lanceolate, fairly thick, 6–12 cm. long, 1–3 cm. broad, often slightly falcate, dull green on both sides, tips brown and withered. Venation fairly distinct, lateral veins arranged at angles of from about 40–55 degrees with the midrib, intramarginal vein usually close to the edge. Oil glands numerous. Petiole from 1–1·5 cm. long.

Buds.—Greenish-brown, almost sessile or with pedicels about 1 mm. long, operculum conoid, 5 to 7 mm. long, the calyx-tube scarcely half that length, peduncle somewhat flattened, about 1 cm. long.

Flowers.—About 7–13 in the umbel, anthers of medium size, the cells parallel.

Fruits.—Almost sessile, hemispherical, about 7 mm. in diameter with usually four exserted valves, rim thick, convex.

Bark.—Thin and smooth to the ground, sometimes ribbony, ·5–2 mm. thick, slaty to greenish in colour.

Timber.—Brown towards centre, tough.

Seedlings.Hypocotyl red, erect, glabrous.




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Cotyledons slightly emarginate, 1·7 mm. long, 5 mm. broad, lobes oblong-obtuse, upper side green, underside red, glabrous; petiole 2 mm. long.

Seedling foliage opposite for two or three pairs, entire, glabrous, oval-lanceolate to ovate and ovate-lanceolate, obtuse. First pair up to 1·4 cm. long, 7·5 mm. broad, upperside green, underside red to purple, petiole 2 mm. long. Second pair up to 3 cm. long, 1·8 cm. broad, underside red to purple, petiole 5 mm. Third pair up to 4·7 cm. long, 2·4 cm. broad, underside at first reddish purple, becoming pale green, petiole up to 7 mm.

Stems red.

The seeds germinated twelve and a half years after being gathered. Plants when about 6–8 inches high developed nodules or swellings about the axis of the cotyledons, which had fallen.

Range.

Near Pokolbin, a quarter of a mile west of portion 146, Parish of Rothbury County of Westmoreland, New South Wales.

This species is a Mallee growing on the side of a hill amongst Eucalyptus siderophloia Benth., E. maculata Hook., Callitris calcarata R.Br., Casuarina Luehmanni R. T. Baker, and C. stricta Ait. The specific name is in allusion to the dwarfed habit of the tree.

Affinities.

1. With E. dealbata A. Cunn.

Its closest affinity appears to be with E. dealbata A. Cunn., from which it differs in bark and timber, as well as the texture of the leaves, and the position of the intramarginal vein. The seedling foliage is also different. (The evolution of the Eucalypts in relation to the cotyledons and seedlings, by Cuthbert Hall, M.D., Proc, Linn. Soc. N.S.W., vol. xxxix, Plate 46). E. dealbata will sometimes grow in Mallee form, but in such cases the bark remains fairly thick, and the timber soft.

2. With E. Behriana F.v.M.

In bark, timber, oil and habit E. pumila much resembles E. Behriana F.v.M., but differs in the flowers, fruits and leaves.

Leaves of this Eucalyptus were procured and distilled in August, 1907, at the Technological Museum. Messrs. Baker and Smith report on the oil as follows:—

The yield of oil is large, 617 lb. of leaves with terminal branchlets giving 9 lb. 10 oz. of oil—equal to 1·56 per cent. The oil is very rich in eucalyptol, and both in yield and eucalyptol content this species is one of the best from which to distil Eucalyptus oil for pharmaceutical purposes, and in this respect may be associated with E. Smithii, E. polybractea (fruticetorum) and E. Morrisii. The oil contains some


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pinene, but the dextrorotatory form only slightly predominates, and consequently the large fraction of rectified oil does not vary but slightly in optical properties from that of the crude oil. This is contrary to the general experience with oils of the eucalyptol class, as in those the dextrorotatory pinene generally predominates. There are only a few species which give an oil, the rectified portion of which has a less dextrorotatory than the crude oil; E. dealbata is one of the species having this peculiarity as well as E. Behriana, E. maculosa, and a few others. No phellandrene could be detected. A small amount of the lower boiling aldehydes was present; the odour indicated that butaldehyde and valeraldehyde were present, thus following the general rule. The crude oil in appearance and other characteristics resembles those of this group generally, and the recified oil is slightly tinted yellow. … Of the most closely allied oils it more nearly approaches E. dealbata than that of any other species which has yet been investigated, although the resemblance between it and the oil of E. Behriana is also strongly marked.

Being a Mallee, it was thought that it might contain a considerable amount of calcium oxalate in the bark. The green bark taken from small sticks had a thickness of 1 to 2 millimetres; it was found to contain 3·85 per cent. of calcium oxalate. The amount of calcium oxalate in the bark of the largest piece having a diameter of 3 inches was 5·39 per cent. The crystals in the bark of this species differ in no respects from those of Eucalyptus barks generally (see paper with plate by H. G. Smith in Journ. Roy. Soc. N.S.W., xxxix, 23, 1905). The amount of lime in the bark of E. dealbata was 1·19 per cent.

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