>o8 



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 1 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 1 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, i8g8. 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 1 volume 80 per cent, alcohol. 

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



