520 



jf/5. Eucalyptus exserta. 



(F.v.M., in Jour. Linn. Soc., 1859, iii, 85.) 



Systematic. A small tree, with an ash-brown, scaly, wrinkled and fissured 

 bark, persistent on trunk and branches. Leaves alternate, narrow-lanceolate, 

 elongated, falcate, acuminate, 3 to 6 inches long, and 4 to 8 lines broad ; venation 

 not prominent, intramarginal vein distant from the edge. Umbels axillary or 

 lateral, three- to seven-flowered, peduncles angular, 3 to 5 lines long. Calyx 

 tube hemispherical, indistinctly ribbed, shortly pedicellate, half as long as the 

 conical, somewhat obtuse operculum. 



Fruit. Hemispherical ; rim broad and very pro- 

 minent, almost conical ; valves much 

 exserted ; 3 to 4 lines in diameter. 



The fruits show a great resemblance to those of E. 

 tereticornis and E. rostrata, but the bark differentiates 

 it from each, being closely allied to the " Bloodwoods." 



Habitat. Eastern portion of Queensland. 



ESSENTIAL OIL. Leaves and terminal branchlets of this species for 

 distillation were received from the Boyne River, Gladstone, Queensland, in 

 September, 1908. The material was sent by Mr. H. S. Owbridge, through Mr. 

 McMahon, the late Director of Forests for that State. The yield of oil was 0-82 

 per cent. 



This Eucalypt is known in the Boyne River District as ' Peppermint," 

 but the oil has no resemblance to those of the members of the "Peppermint" 

 group growing in the Southern States. 



The crude oil was reddish in colour, and had an odour resembling the cineol- 

 pinene oils generally. The constituents present were cineol, pinene, aroma- 

 dendral, and the sesquiterpene ; volatile aldehydes were pronounced, and cymene 

 was probably also present. 



The crude oil had specific gravity at 15 C. = 0-8977; rotation a D + 12-2; 

 refractive index at 20 = 1-4729, and was soluble in 5 volumes 80 percent, alcohol. 

 The saponification number for the esters and free acid was 4-7. 



On rectification, 2 per cent, distilled below 161 C. (corr.). Between 



161-167, 40 per cent, distilled ; between 167-174, 24 per cent, came over ; 



between 174-183, 16 per cent, distilled; between 183-228, 8 per cent, distilled, 



and between 228-255, 6 per cent. These fractions gave the following results : 



First fraction, sp. gr. at 15 C. = 0-8833; rotation D + 19-8; refractive 



index at 20 -- 1-4689. 

 Second ,, ,, ,, = 0-8902; rotation CI D -+- 14-5; refractive 



index at 20 = 1-4703. 

 Third ,, ,, ,, = 0-9039; rotation c,, + 3-9; refractive 



index at 20 = 1-4719. 

 Fourth ,, ,, ,, - 0-9310; rotation a 7'6; refractive 



index at 20 = 1-4821. 

 Fifth ,, ,, ,, = 0-9485; rotation <? D 2-0; refractive 



index at 20 = 1-5005. 



The cineol was determined by the phosphoric acid method ; the result was 

 29 per cent, in the crude oil. 



The laevo-rotation of the higher fractions was due to the aromadendral. 

 The oil of this species does not contain phellandrene, nor was eudesmol detected. 



