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A SHORT DICHOTOMOUS KEY TO THE HITHERTO 

 KNOWN SPECIES OF EUCALYPTUS. 



By J. G. LUEHMANN, F.L.S. (Curator, National Herbarium, 

 Melbourne.) 



(Read before the Australasian Association for the Advancement, of Science, 

 Tuesday, January 11, 1898.) 



THE scheme herewith laid before the members of the Association, 

 to classify the species of the genus Eucalyptus according to the 

 fruits, is not, I may state at the outset, meant to supersede the 

 excellent anther-system introduced by Bentharn ; the latter being 

 in my opinion the most reliable which, with our present know- 

 ledge, can be devised. Frequently, however, when specimens are 

 gathered, expanded flowers, or even well-advanced buds, are not 

 available, while nearly every adult tree bears fruits as well as 

 young flower-buds, and in most cases, though not in all, the species 

 can by their aid and that of the leaves be determined with toler- 

 able accuracy. The present arrangement should, therefore, be 

 looked upon as devised to act as an auxiliary guide only, without 

 any full descriptions, and is for this reason submitted in the form 

 of a key. The primary character chosen is that of the fruit-valves, 

 whether quite enclosed or whether the points protrude beyond the 

 rim, or whether the top of the fruit is convex with every part 

 raised above the rim ; secondarily, the shape and size .of the fruit 

 are taken into consideration. De Candolle's classification, based 

 on the shape of the operculum, is relied upon for further sectional 

 divisions. While the majority of the species are without difficulty 

 assigned to their respective divisions, there are others which form 

 a transit and, in these cases doubts will arise, especially when 

 we consider their remarkable variability. Even with complete 

 material I have sometimes found it difficult to fix the limits of a 

 species, although I devoted a great deal of time to the study to 

 the genus while assisting the late Baron von Mueller in the 

 elaboration of his Eucalyptographia, for which I worked up the 

 very extensive material that had accumulated since the publica- 

 tion of the third volume of the Flora Australiensis. This mut- 

 ability of form is well illustrated by the fact that a dozen kinds, 

 raised from Australian seeds, have been described as new species 

 in Europe and America by botanists of repute, although it seems 

 improbable that they would receive seeds of a single species that 

 had not already come under Baron von Mueller's notice. While 



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