THE BOLIVIAN SPECIES OF VERNONIA 
Henry Allan Gleason 
(Received for publication October 2, 1922) 
Rapid progress has been made in extending knowledge of the flora of 
Bolivia during the past quarter-century. Bang and Buchtien, stationed in 
the country, have distributed numerous specimens, several European 
botanists have collected in it, particularly along its southern boundary, 
and the expeditions of Rusby, Williams, and White have been especially 
productive. While many parts of its great extent are practically unknown 
botanically and will doubtless yield many unreported species, it may be 
desirable to summarize the species of Vernonia so far as they are at present 
represented at the New York Botanical Garden. 
This vast genus is greatly developed in southern Brazil, Paraguay, and 
Uruguay, where it forms one of the most important components of the flora. 
These areas have mostly been approached from the east, and it is not known 
how many of their species extend westward into Bolivia. Another center 
of development is along the Andean chain of mountains, from Colombia to 
Bolivia. Since the mountainous portion of Bolivia has been more thor¬ 
oughly botanized than the eastern portion of the country, the species of 
this general distribution and relationship are better known. 
Lying at the western limits of the Vernoniae of the Brazilian center, 
and at the southern, extremity of those of the Andean region, Bolivia 
exhibits only the end results of evolution, and the species give little clue 
accordingly to their mutual relationships within the genus. The following 
arrangement of species may need considerable revision after careful study 
has been made of the probable evolution of the Brazilian species. 
The three sections Stenocephalum, Critoniopsis, and Lepidaploa have 
been distinguished on the usual morphological characters. Within the 
last-named section, groups have been segregated according to the inflores¬ 
cence, since experience with North American species has indicated that this 
character may be of great evolutionary importance. 
Thanks are due to Dr. William R. Maxon for the loan of material from 
the Buchtien Herbarium, recently acquired by the National Museum. 
Involucre cvlindric, few-flowered, its scales closely imbri¬ 
cate, permanently erect, coriaceous, subulate or spinose 
at the tip; inflorescence spicate. Section 1. Stenocephalum. 
Involucres small, of few but imbricate scales, the inner 
deciduous at maturity, the outer eventually spreading, or 
permanently erect; pappus fragile, the outer series poorly 
differentiated; inflorescence a widely and freely branched 
compound cyme. Section 2. Critoniopsis. 
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