(165 ) 
Schreber to receive a binomial name. A large number of generic 
synonyms belong to the genus as a whole, but only five of these 
apply to North American species. Suprago Gaertn. was pub- 
lished in the same year as Vernonia, and there is apparently no 
evidence which of them is the older. It is typified by Suprago 
glauca (V. glauca Willd.). Baccharotdes and Ascaricida both 
refer to V. anthelmintica, Lepidapiloa is based on V. scorpiotdes, 
and since the publication of the Prodromus has been used as a sec- 
tional name. The identity of Cassini’s Achyrocoma tomentosa 
(V. Achyrocoma Lessing) is uncertain and the name is treated here 
as a nomen nudum 
The genus Vermonia, even after the segregation of the forms 
here placed in Lachnorhiza, Letboldia and Eremosés, is still a 
huge aggregation presenting striking variation in the structure of 
the inflorescence and involucre. Comparing some of the extreme 
forms, such as V. dahamensis, V. arborescens and V. crinita, 
the diversity seems almost sufficient to warrant their separation into 
distinct genera. Eight genera could be constructed from the North 
American species if these extremes were taken as types. But ex- 
amination of all the species shows that these diverse forms are all 
derived one from the other and in most cases it is easy to trace the 
connecting links. V. dahamensts and its relatives, here placed in 
the subsection Scorpiotdeae reductae, may be easily connected 
through V. adbzcaudés to normal scorpioid forms; V. duxtfolia and 
the allied species, constituting the Scorpzo¢deae aggregatae, show 
a similar relationship through V. acuminata. e close relation- 
ship of the Scorpzoideae foliatae and Scorpioideae aphyllae is 
obvious. By repeated branching of the cymes in the latter arise 
such forms as V. cazescens, in which the inflorescence assumes a 
pseudo-paniculate appearance. By the shortening of the individual 
cymes an inflorescence like that of V. scaéra is produced; from 
that to the true Paxiculatae is but a short step. There is, accord- 
ingly, from one extreme to the other an almost unbroken series of 
intermediate forms making the segregation of genera impossible. 
The two Old World species, V. anthelmintica and V. cinerea, 
belong to different sections of the genus and there are stronger 
reasons for removing them, an action which has however been 
deemed inadvisable. 
ithin this vast assemblage certain groups of species stand in 
relief from their marked resemblance one to the other. As a con- 
