An Index to the described Species of Botrychium 
By Lucien MArcus UNDERWOOD 
During seven years of special but more or less interrupted 
study of the genus Botrychium added to a field experience with 
various members of the genus extending over a quarter of a cen- 
tury, we have been able to see the most important collections of 
the world and have received a great quantity of material from 
numerous correspondents. Besides practically all the herbaria of 
this country, the foreign collections at Kew, London, Berlin, and 
Paris have been studied with care. As a result of this study not 
only have our former convictions regarding the status of the 
various members of the vamosum and ternatum groups been con- 
firmed, but additional species in both these groups, together with 
two new representatives of the Virginianum group can now be 
properly segregated. 
With the most recent publication of an African species, some 
members of the genus are now found on every continent and in 
every zone in which a land-area exists. The first index to the 
species was published by Milde,* who early gave an elaborate’ 
account of the variations of the species known to him. Great 
authority has hitherto been attributed to his opinions, which he 
published a generation ago, but it must ever be remembered that 
he based his conclusions, except among the central European spe- 
cies which he knew in the field, on exceedingly meagre data. This 
is especially true of American material, particularly among the 
smaller species of the genus. The same condition remains true 
to this day regarding the greater part of the collections of con- 
tinental Europe. When we examined the collection at Berlin in 
1898 it contained only a single American specimen of Botrychium 
fanceolatum and that from Greenland, and not a single specimen 
of B. neglectum. Milde’s collection was scarcely better, to judge 
it by his own citations, and the futility of relying on opinions based 
on such meagre data becomes clearly apparent when we know 
* Verhandl. k. k. zool.-bot. Gesell. Wien. 18: 507-516. 1868. 
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