(146) 
(1), Pacourina (1), Piptocarpha (30), Pseudelephantopus (2), 
Rolandra (1), Spiracantha (1), Struchium (1). 
Endemic to West Indies: Piptocoma (1). 
Endemic to Mexico: Molanosa (1), Eremosts (15), Letboldia 
3). 
Endemic to the United States: Stoesta (1). 
Both hemispheres: Centratherum (12), Elephantopus (14), 
Lachnorhiza (2), Vernonia (+ 600). 
It seems very probable that the Asiatic species included under 
Centratherum are not strictly congeneric with the American forms, 
and that the African plant referred to Lachnorhiza is rather to be 
placed in Vernonia. 
The distribution of genera shows at once the two centers of 
distribution, one in Africa, the other in South America. Further 
details on geographical distribution will be given under the dif- 
ferent genera. 
The nomenclatorial history of the tribe begins with the first edi- 
tion of Linnaeus’ Species Plantarum in 1753, in which several 
species are described under various generic names. During the 
subsequent seventy years more than a hundred species were de- 
scribed and the principal genera were separated. Nevertheless the 
first consistent attempt at a logical classification is that of Lessing * 
in 1829. His first division, based on the presence or absence of 
so-called bracteoles, is no longer followed, but his subsequent divi- 
sions follow more or less closely the characters used by Bentham 
and Hooker and by Hoffmann. Lessing distinguished 28 genera, 
some of which are not properly included under the Vernonieae, 
and was also the first to bring together under Verzonia the various 
species described previously under Serratula, Conyza, Achyro- 
coma aud Lepidaploa. Lessing continued his publications in 
Linnaea and in volume 6 gave a second conspectus of the tribe, 
recognizing the subtribes Vernonieae, Elephantopeae, Tricho- 
spireae, Rolandreae, Liabeae and Pectideae. His descriptions of 
species are full and his citations of synonymy usually very acctrate. 
Lessing’s work was followed by that of De Candolle, who in 
1836 monographed the tribe in volume 5 of the Prodromus. His 
Tribus Vernoniaceae was characterized by the subulate styles, and 
* De Synanthereis Herbarii Regii Berolinensis. Linnaea 4: 240-356. 
