TYPE SPECIES OF THE FIRST ioo GENERA OF LINNAEUS’ 
SPECIES PLANTARUM 
A. S. Hitchcock 
(Received for publication January 6, 1923) 
The type concept is finding increasing favor with botanists everywhere. 
So far as its application to future cases is concerned it may be regarded as 
already accepted. But when it comes to applying the principle retro¬ 
actively there is some hesitation on the part of many. Because of the way 
in which it has been applied by some of the adherents of the American Code, 
there has been a fear that many well-established names might be superseded 
if the method were generally used. The rules of the Type-basis Code are 
more elastic than those of the American Code and would permit a reasonable 
application of the principle without introducing unnecessary confusion. 
In my account of the Genera of the Grasses of the United States 1 I typified 
about 300 genera of grasses according to the rules set forth in the Type- 
basis Code. In order to test the effect of applying these rules to other 
genera of flowering plants, I have tentatively typified the first 100 genera of 
Linnaeus’ Species Plantarum. The results are here set forth and analyzed. 
Of the 100 genera, 28 contain a single species. These are the types of 
the respective genera according to any set of rules. Most botanists agree 
that a generic name should be applied so as to include its original species 
when there is only one, and one of its original species where there are more 
than one. However, there are a few cases in which the historic development 
has followed a different course. An application of the type concept may 
here cause a profound dislocation of names if a large number of species are 
involved. Such cases should be considered on their merits and exceptions 
made if it seems worth while and if a general agreement can be reached. 
Among the genera mentioned (often called monotypic genera), there are 
two cases in which the original species is not included in the genus as now 
generally accepted. Since the original species is in each case the type, an 
application of the type concept necessitates a readjustment of the nomen¬ 
clature of each group. Alpinia racemosa, the single species of Alpinia, is 
now referred to Renealmia, though the genus Alpinia, containing a large 
number of species, is recognized as valid. Dr. E. D. Merrill has called 
attention to this case. Among the genera of group 1 there is one other case 
of this kind, Eranthemum capense , referred to Daedalacanthus, though the 
genus Eranthemum with many species is accepted as valid. 
1 U. S. Dept. Agr. Bull. 772. 1920. 
510 
