STUDIES IN THE COMPOSITAE. 263 
of plants inhabiting each its own section of U. S. territory 
and of adjacent Canada and Mexico; but the segregates 
that may easily be established do not seem to be as numer- 
ous as in the case of the aggregate B. cernua; and in an at- 
tempt to make out the species, and assign them names, one 
encounters difficulty in ascertaining to what plants certain 
old names really belong. Where this kind of difficulty 
amounts to a problem that can not be solved, there is plainly 
nothing to be done but to reject such name altogether, if 
one is to act rationally and philosophically. A name is not 
published, if it be not accompanied by a diagnosis such as 
enables a competent master of descriptive terminology to 
identify the species by it. 
And who will assert that Linneus’ Helianthus levis can 
be determined, from the description, either as given by him 
or implied, to be identical with Bidens chrysanthemoides? 
The answer that there is one herbarium fragment extant 
beyond the sea that proves it, is but an evasion; for the 
placing of a specimen in an herbarium, with a name, does 
not constitute publication. The name B. levis should be dis- 
continued, and will be, by as many as regard reason and 
use goód sense in such a matter. 
With Walter (1785) there is found a Coreopsis perfoliata 
which, the description itself being duly considered, must be 
understood as applying to some Bidens of this group. It is 
credited with oblong-lanceolate leaves undivided and partly 
connate, and with a pappus of two awns; it must therefore 
be some member of the B. chyrsanthemoides aggregate; but 
to none of the several segregates could it warrantably be 
applied ; therefore it should be permitted to remain at rest. 
It is at best, like most of Walter's names, a nomen semi- 
nudum. 
Just what one of the several segregates which I might 
