6 ARKIV FOR BOTANIK. BAND 13. N:0 15. 



The differences existing as to the shape of corollas, size 

 of anthers etc. have been generally regarded as being of little 

 importance in delimitating species and groups in Vernonia. 

 In order to ascertain if these characters actually have no 

 value, I have analyzed numbers of flowers of all the species 

 mentioned in this paper, and of many South American ones. In 

 general, the characters found agree with those of habit and 

 inflorescence, and no striking results have been obtained. 

 Yet they have proved to be of same value for recognizing 

 smaller groups of the subsections and for identifying the spe- 

 cies. More interesting is the fact stated through these exam- 

 inations of flowers that the basal lobes of the anthers, which 

 are said to be obtuse in Vernonia, sharply acute in Pipto- 

 carpha, very often are acute in Vernonia too. This should 

 mean that the only difference between Piptocarpha and Ver- 

 nonia vanishes. I hope I shall have an opportunity to 

 return to this in another paper. 



As characters of the flowers are seldom mentioned in 

 the descriptions of Vernoniae, I have under each species' 

 listed in this paper given its analytical distinctions. 



As to the species themselves, there will be found to exist 

 a certain difference between my treatment of the West In- 

 dian ones and that of Gleason, not only in regard to their 

 names, but to their delimitation. In Gleason's paper the 

 species are very small, narrowly defined and, as a rule, based 

 upon a very meagre material; my species are in general 

 much wider, including several forms described b} T him as 

 proper species. Yet my work also has been compiled upon 

 the principle: to separate what can be separated practically. 

 It may be that Gleason has another conception of species 

 than I have, as North American botanists on that point often 

 differ from European ones (cfr. Otto Kuntze, Rev. gen. 

 plant., Band III 11 , 1898, p. 144, the note). It is, possibly, be- 

 yond his reach to conceive, for instance, the striking common 

 features of his V. arborescens, V. intonsa, V. permollis, V. 

 albicoma and V . amaranthina, which is the evidence of their 

 being all merely forms of one species. He keeps, apparently, 

 his mind open to the differences, not to the affinities. But 

 he will, I am sure, not fail to find that, with the descrip- 

 tion of new species like the above mentioned, the delimita- 

 tion of the already existing ones will become always more 



