(F.v.M., in Trans., Vict. Inst., 32, 1855.)

Systematic. - A shrubby tree, though sometimes found up to 50 feet in height. Bark smooth (decorticating in thin flakes or sheets). Abnormal leaves, broad, oval-cordate, sessile, crenulate, scabrous, branchlets much flanged. Normal leaves ovate-lanceolate, acuminate, pale green on either side; intra-marginal vein well removed from the edge, lateral veins generally at an angle of 450 with the midrib. Buds large, usually three, sessile or almost so, common peduncle flattened; calyx tube conical, rough, often ridged, about 5 lines long; operculum almost hemispherical, shortly pointed.

Fruit. - Semi-ovate, almost hemispherical, occasionally ribbed; rim bevelled or flat, outer edge sometimes forming into a flange; valves depressed or slightly ex-serted; about 6 lines long and 6 lines broad.

In the larger form the fruit resembles those of E. longifolia, but the hemispherical more closely perhaps those of E. ovata, Labill., Western Australia, collected by Mueller.

Habitat. - Kangaroo Island and ranges near Adelaide, South Australia.

95 Eucalyptus cosmophylla 151

REMARKS.- - This species is endemic to South Australia, and is easy of determination, both in the herbarium and field, by its specific characters.

ESSENTIAL OIL. - Material consisting of the leaves and terminal branch-lets for distillation was received from the Conservator of Forests of South Australia, Mr. Walter Gill. The material was collected in December, 1911. The yield of oil was 0.62 per cent. The crude oil was light orange-brown in colour, with an odour indicative of an oil belonging to the cineol-pinene group, with a secondary one suggestive of the aldehyde aromadendral. The presence of volatile aldehydes was particularly marked. The slight laevo-rotation of the crude oil was evidently due to the aromadendral, although the pinene was also lævo-rotatory to a small extent; phellandrene was absent. This left rotation is unusual with oils of this class, as in most cases the pinene shows a predominant dextro-rotation. The cineol content was only fair, and the oil did not contain constituents having special characters; the species has, therefore, little value as an oil-producing tree.

The crude oil had specific gravity at 150 C. = 0.9108; rotation aD - 3.2°; refractive index at 200 = 1.4659, and was soluble in 7 volumes 70 percent, alcohol. The saponification number for the esters and free acid was 5.6.

On rectification, a few drops of acid water, together with some aldehydes, came over below 1670 (corr.). Between 167-1720, 9 per cent. distilled; between 172-1980, 75 per cent. came over, and between 198-2700, 11 per cent. distilled. These fractions gave the following results: -

First fraction, sp. gr. at 150 C.

=

0.8909; rotation aD - 2.6°; refractive index at 200 = 1.4612.

Second

"

"

"

=

0.9065; rotation aD - 3.0°; refractive index at 200 = 1.4628.

Third

"

"

"

=

0.9296; rotation aD - 3.3°; refractive index at 200 = 1.4827.

The cineol was determined by the resorcinol method in the rectified portion, and calculated for the crude oil; the result was 50 per cent. By the phosphoric acid method it was 43 per cent, when calculated for the crude oil.

The rectified oil was tinged yellow, a peculiarity common with the oils of this group. This colour is traceable to quinone influence, derived from the phenol present in the oils of certain groups of the cineol class, but is not shown by the oils from the "Peppermints" or the "Ashes."

The results obtained with the oil of this species were published by us in the Trans. Roy. Soc, South Australia, 1916.