column: but you will find various degrees of separation 
between those parts. . .”’ in several species **. . . which 
nobody can doubt are genuine Lpidendra... Should 
you, however, be of opinion that it nevertheless must 
form a new Genus, its character will have to depend 
upon the large size of the peta/s and the slight adhesion 
of the sepals at their base.*” Seven years later, Lindley 
erected his subgeneric concept Diacrium on the basis of 
Epidendrum bicornutum. 'Then, in 1881, when he raised 
Diacrium to generic status, Bentham wrote that “‘the 
peculiar bicornute labellum, neither adnate to nor paral- 
lel with the column, gives the flower a very different 
aspect from that of true species of Hpidendrum and can 
not be included in them without doing violence to the 
generic character.’ 
Having now at hand material from a wide geographic 
range—all with certain diagnostic characters which show 
no variation—I believe that the best interests of orchid 
classification may be served by keeping the concept dis- 
tinct on a generic level. It is obviously very closely allied 
to Mpidendrum, and some of the differences used to sep- 
arate it may appear to be superficial. Nevertheless, it 
would seem that they represent perhaps a definite tan- 
gential evolutionary trend which ought to be recognized. 
There can be no doubt that Caularthron should be used 
as the name for this generic concept in preference to 
Diacrium. There is a widespread aversion to the accept- 
ance of many names proposed by Rafinesque. But I am 
sure that most botanists will agree with Merrill (Merrill, 
E.D.: ‘‘Index Rafinesquianus’’ (1949) 26, 29) that “*... 
where a new Rafinesque name was based wholly on a 
previously described or illustrated species of some other 
author, all we have to do to understand the application 
of the Rafinesque name is to determine the status of the 
originally described form . . . Thus it seems to be a logi- 
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