18 



MB. J. BALL ON THE T'LOBA 



peculiar to the Andes, but the proportion of species belonging to 

 cosmopolitan genera would not probably have been very much 

 reduced. I have tabulated the proportions found in the ' Chloris 

 Andina ' for genera and species belonging to the gamopetalous 

 dicotyledons which here constitute about one half of the entire 

 phsenogamous flora. 



Analysis of the Genera and Species of Gamopetalous Dicotyledons 



in the Andean ~Plora. 



Cosmopolitan genera 

 Ampliigean genera . 



Number of 

 genera. 



Wide-spread American genera. 

 Antarctic genera 



Andean genera 



Totals 



34 

 5 



17 



G 



62 



124 



If umber of species 

 in Andean flora. 



422 

 50 

 76 



57 

 274 



879 



It will be recollected that this table includes a large proportion 

 of the Chilian flora, in which the endemic elements are much more 

 strongly marked than in the Equatorial Andes, Yet even here, 

 we find nearly one half of the species belonging to 34 cosmopolitan 

 genera, a full third being supplied by the 6 genera Valeriana^ 

 Gentiana^ Bartsia^ JErigeron^ Gnaplialiiim^ and Senecio; while 

 mucli less than a third of the species are ranked under the 62 

 endemic genera of the Andeau flora. 



I may here remark that, so far as the available materials admit 

 of comparison, the Andean flora appears to be one of the most 

 distinct existing in the world, if we take the proportions of en- 

 demic genera and species as criteria. It would appear that about 

 one half of the genera aud fully four fifths of the species are 

 limited to that region, showing a degree of separateness scarcely 

 surpassed elsewhere. Allowing for the fact that the endemic 

 elements of the flora of each large region are more conspicuous 

 in the mountains than in the low country, it is remarkable thai, 

 comparing the same large group of Gamojpetalce in the Australian 

 and Andean floras, we find in the first only 97 endemic genera 

 out of a total number of 353, while in the latter one half of the 

 genera are endemic. 



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