Australian Flowering Plants. 229 



as belonging to several species. Bentham also, in his Flora 

 Australiensis, included many forms under one species in vari- 

 ous genera and families. Cheeseman also appears to have 

 experienced the same difficulty in the preparation of his 

 "Hand Book of the New Zealand Flora. " This solution is 

 unsatisfactory, however, inasmuch as it simply suggests to the 

 observer that there are many perplexing forms belonging to 

 the one species or genus. 



It is probable that the solution is to be found by a knowledge 

 of the geographic and oedaphic, as well as of the morphological, 

 and chemical, factors. Thus, when the botanist, who may be 

 studying Acacia, learns that there has been a great revolution 

 in the topography of Eastern Australia by the formation there 

 of high plateaus in late and post-Tertiary time, with the con- 

 sequent production of a threefold climate in the same region, 

 namely, mild and moist along the coast, cold and bleak on the 

 plateau heights, and relatively dry and hot on the western 

 slopes, and he knows, moreover, that a variety of Acacia longi- 

 folia is recorded from the mountains, another from the coast 

 and still another from the creek banks, then he may be coura- 

 geous and separate all as species, recognizing each as under- 

 going transition or saltation during the present time. Or when 

 Acacia salicina is seen as a handsome tree on the deep, loamy 

 soils of the watercourses, and as a straggling plant on the dry 

 barren sandstones of the interior, the two having very different 

 appearances, then A. salicina of the loam may be considered 

 as an adaptation of the sandy form to a more congenial habitat, 

 and as one which either is, or soon will be, a species different 

 from the old type of the barren hillsides. Eucalyptus albens 

 and E. hemiphloia admit of similar treatment. Or again, if 

 species of Eucalyptus, such as E. amygdalina, E. coriacea, and 

 others, should show differences on the mainland of Australia 

 from similar forms in Tasmania such that confusion should 

 be caused among systematists as to their proper relations to 

 each other, then it might be advisable to consider the allied 

 types in the two regions as having been the one species in recent 

 time when Tasmania was connected to the mainland by a narrow 

 neck of land and that geographic isolation under different cli- 

 matic environment in the two regions is now converting certain 

 individual species into two. 



Similarly Veronica, Epilobium, Coprosma, and other genera, 

 in New Zealand might be treated advantageously in this man- 

 ner. In other words, the geographical station of the plant, the 

 peculiarities of that station with respect to other stations con- 



