STUDIES IN THE COMPOSIT.E. 253 
so different in aspect, even as seen in the herbarium, that I 
can no longer doubt that they arealtogether distinct. This 
difference is so pronounced, even upon the face of dry ma- 
terial, that I imagine any botanist familiar with ours, on 
being introduced to the Old World plant alive and fresh, 
would be forced to admit that he had never before seen B. 
cernua.: I shall not attempt an analysis here, of the several 
marks which combine to give its characteristic facies to the 
Old World plant; but any competent botanist who may 
care to investigate the case, may do this for himself, if he 
have access to an herbarium in which both are represented. 
In studying our North American cernuous forms, I have 
become aware of the presence of characters not before ob- 
served or mentioned, but upon which it is necessary to pro- 
pose new species. One of these is marked by singularly 
long and narrow ray-corollas. Others exhibit such charac- 
ters of achene and awns as it is impossible not to interpret 
as of specific import; for example, the achenes in one are 
black and smooth, in another brown or greenish and strongly 
striate. While in some the achene is compressed and with 
only two of the angles prominent and retrorse-barbed, in 
others it is more evenly four-angled and with all the angles 
barbed. Again, the angles are suberous-thickened in some, 
in others not at all so; and the awns themselves, as to their 
relative, and also as to their absolute proportions, their tex- 
ture and their color, are very different in plants of different 
habit and diverse geographical range. 
The varieties proposed by Mr. Wiegand are such aggre- 
gates of true species, some of them most excellent, that I am 
obliged to decline attempting to perpetuate the varietal 
name in either case. And this I can do with the best of 
good conscience since I have always denied that there is any 
obligation to elevate varietal names to specific rank when 
the varieties themselves are thus promoted. 
