This section is from the book "A Research On The Eucalypts Especially In Regard To Their Essential Oils", by Richard T. Baker, Henry G. Smith. Also available from Amazon: A Research On The Eucalypts And Their Essential Oils.
(R.T.B. & H.G.S., in Euc. and their Ess. Oils, Edit. 1902, p. 127.)
Systematic. - This variety is distinguished from the type by its having two opercula to each bud and by the difference in its oil. The outer operculum is thin, and is shed very early in the budding stage, so that it is scarcely ever to be found in herbarium material. The fruit always has a broad groove below the rim, and like the leaves are always larger and thicker than those of the type, while the wood is more open in the grain and less interlocked. Otherwise, morphologically, there is little to distinguish it from the type.
Habitat. Blue Mountains, Rylstone, Barber's Creek, Lismore, Colo Vale, New South Wales.
ESSENTIAL OIL. - The oil obtained from this variety of E. punctata, from material collected at various localities outside the Sydney district, differed considerably from that obtained from the type growing in the neighbourhood of Sydney. Although the constituents were similar in both cases, yet they varied greatly in the amounts, and the cineol in the oil of the variety was considerably less than in that of E. punctata itself.
The presence of aromadendral was very marked, so much so that the odour of the crude oils resembled those obtained from the true "Boxes," rather than from the "Gums." Pinene was present in some quantity, but phellandrene was absent.
Material was obtained from the following localities in New South Wales: - Colo Vale, in July, 1900; Rylstone, in August, 1897, and Barber's Creek, in July, 1898. The oils from these were very similar, and all gave practically the same results. When tabulated it can be seen how well they agree in general characters, although extending over a period of three years, and from three different localities: -
Yield of Oil per cent.
Specific Gravity at
15° C. Crude Oil.
E. punctata, var. didyma -
Rylstone, 3-8-1897. ......
Not exceeding 10 %
E. punctata, var. didyma- -
Barber's Creek, 12-7-1898
+ - o°
Not exceeding 10 %
E. punctata, var. didyma - •
Colo Vale, 4-7-1900 .......
73% + 0.4°
The solubility ranged from 7 volumes 70 per cent, alcohol to 2 volumes 80 per cent, alcohol, and saponification number from 10-9 to 11.6.
This variety of E. punctata is apparently a tree not far removed, chemically, from some of the typical "Boxes"; other evidences also go to show the close relationship existing between the "Gums" and the "Boxes."
That alcoholic bodies were present in some quantity is indicated by the results after acetylation of these mixed oils. The saponification number was then 57.6.