154 



82. Eucalyptus Muelleri. 



(T. B. Moore, in Roy. Soc., Tas., 207, 1886.) 

 Brown Gum. 



Systematic. A large tree, attaining a height of 200 feet. Bark scaly at 

 base, smooth above, reddish in colour, often blotched. Abnormal leaves, usually 

 opposite, rounded or oval, crenulate, mucronate, sometimes cordate, sessile 

 or shortly petiolate, averaging about 2 inches long and i-| inch broad. Normal 

 leaves ovate to lanceolate, thick, shining ; venation not pronounced, intramarginal 

 vein somewhat removed from the edge, lateral veins inclined at an angle of about 

 30 to the mid-rib. Flowers sessile, usually in threes, short, broad, angular, on 

 axillary peduncles about 2 lines long. Buds reddish in colour ; calyx tube almost 

 hemispherical, flanged, about 2 lines long ; operculum domed at first, surmounted 

 by a blunt point. 



Fruit. Compressed, hemispherical, or semi-ovoid, 

 sometimes ridged ; rim convex ; valves 

 thick, exserted ; about 3 lines long and 

 4 lines in diameter. 



The nearest in form is perhaps E. Baeuerleni or even 

 E. unialata. 



Habitat. Tasmania, high situations. 



REMARKS. Mueller, and now later systematists are inclined to regard this species as identical with 

 E. vernicosa, and the oils do not assist much in their separation, hut otherwise we fail to detect any other common 

 character. The leaves, buds, and fruits of E. vernicosa have no resemblance whatever to those of E. Muelleri. 

 The timber and bark are different, and further, the latter is a tree and E. vernicosa a " Mallee." 



When planted in other countries they both grow true to the original and show no variation or gradation into 

 each other. 



ESSENTIAL OIL. Material of this species for distillation was obtained 

 from Mt. Wellington, Tasmania, at an altitude of about 3,000 feet ; it was 

 collected in July, 1908. The principal constituent in the oil was cineol, 

 together with a fairly large amount of pinene. Phellandrene was not present, 

 nor was it to be expected, judging from the botanical features of the species. 

 There was rather a large amount of ester for oils of this class, and this appeared 

 to be largely geranyl-acetate, as it was mostly saponified in the cold with two 

 hours' contact. The crude oil was of a light-amber colour, and had an odour 

 resembling those belonging to the pinene-cineol group. Volatile aldehydes were 

 present, but could be separated without difficulty on redistillation. 



The yield of oil from leaves and terminal branchlets was I-.28 per cent. 

 The crude oil had specific gravity at 15 C. = 0-9096; rotation a D -f- 10-4; 

 refractive index at 20 = 1-4647, and was soluble in 4 volumes 70 per cent, 

 alcohol. The saponification number for the esters and free acid was 15-3, while in 

 the cold with two hours' contact it was 11-7. 



On rectification, the usual amount of acid water and volatile aldehydes 

 came over below 166 C. (corr.), at which temperature the oil commenced to 

 distil. Between 166-173, 44 per cent, distilled; between 173-195, 45 per cent. ; 



