208 



107. Eucalyptus tereticornis, 



(Sm., Bot. Nov. Holl. 41 (1793), and in Trans. Linn. Soc., iii, 284.) 

 Forest Red Gum. 



Systematic. A tall tree with a smooth bark, although occasionally rough at 

 the base. Abnormal leaves orbicular to broadly lanceolate, 4 inches in diameter 

 and under 6 inches long, sometimes oblique ; venation very pronounced on the 

 under side, oblique, spreading, intramarginal vein removed from the edge 

 Normal leaves lanceolate, measuring up to i foot in length and over 2 inches in 

 width; venation distinct, spreading, oblique, intramarginal vein removed from 

 the edge. Inflorescence either on axillary peduncles or in terminal panicles. 

 Peduncles flattened, varying in length up to 9 lines, with seven to nine flowers 

 in the umbel. Calyx tube hemispherical, up to 2 lines in diameter, pedicel variable 

 in length, from under i line to over 3 lines; operculum conical, up to 5 or -6 lines 

 long, acute or obtuse. 



Fruit. Pedicellate, hemispherical ; rim domed ; 

 valves well exserted, acute ; 2 to 4 lines in 

 diameter. 



An easily recognised fruit, with its prominently exserted 

 valves. It more particularly resembles E. rostrata 

 and, E. Seeana, than any other species. 



Habitat. Coastal range and districts of New South Wales; 

 Victoria; Queensland; Papua (J.H.M.). 



REMARKS. The type is well defined and widely distributed in Eastern Australia, the broad abnormal 

 leaves, and long, conical operculum being very characteristic. 



ESSENTIAL OIL. Leaves and terminal branchlets for distillation were 

 obtained from Barber's Creek, N.S.W., in June, 1898. The yield of oil was 0-5 

 per cent. The crude oil was of an orange-brown colour, and had a marked odour 

 of aromadendral. Phellandrene does not appear to occur in the oil of this species, 

 but pinene was present in small amount , cymene was also a constituent of the oil. 

 Cineol was detected, but the amount did not exceed 10 per cent, in the first 

 fraction. Esters occur in some quantity. Aromadendral was a pronounced 

 constituent in the third fraction, from which it was isolated in a pure condition, 

 and its chemical compounds prepared. The oil of this species was almost 

 identical with that obtained from the variety didyma of E. punctata ; it has little 

 commercial value at present. 



The crude oil had specific gravity at 15 C. = 0-9218; rotation a D -- 9-4; 

 refractive index at 20 = 1-4877, and was soluble in i volume 80 per cent, alcohol. 

 The saponification number for the esters and free acid was 26-7. 



