64 NOTES ON OUR LOCAL PLANTS 
old names Quinquefolium or Pentaphyllum. We can not be pre- 
sumed to give reasons for the arbitarry method of Linnaeus in 
this case nor in hundreds of other cases, any more than we wish 
to presume to explain the arbitrary methods of selections of his 
types, by his modern followers. It can not be done logically, 
but we believe that he is to be presumed to want to have the 
name of a genus left to the group or plant that had it before. Dr. 
Rydberg? dismisses the whole pre-Iinnaean history of the group 
because the plants were in “such a chaotic condition that it would 
be impossible to write a history of any value.”’ This is a very 
expedite way of settling a problem, but it will never help settle 
confusion in the long run. As long as we resort to methods of 
expediency in clearing up problems, rather than by applying 
logical principles we are making confusion worse confounded. 
On a number of occasions we have quoted Linnaeus himself 
writing both before and after 1753 as to his idea of method to be 
followed in segregating his genera. In the Philosophia Botanica 
p. 197 of both editions, 1751and 1755, he says: “Si genus receptum 
secondum jus naturae, and artis in plurima dirimi debet, tum nomen 
antea commune manebit vulgatissimae et officinalt plantae. In 
the Hortius Cliffortianus his most careful work Potentilla Anserina 
is the first plant mentioned. Only a one-named designation is 
given in the Species Plantarum as synonym thus intimating that 
it was the Potentilla par excellence in his opinion, as it was deemed 
fit to give the name to the group. Of course we are not even 
supposed according to the theory of residues and the peculiar 
methods of interpretation of priority to allow Linnaeus to correct 
his own mistakes or determine his own types when as seldom he 
does not seem at least to intimate an opinion in the matter. 
There is, however, still another point to make and that is 
that in assigning the theory of residues to effect segregation, the 
author of the illustrated flora is not consistent. 
The segregated genus. Argentina is attributed to Lamarck 
(1778). Pentaphyllum and Quinquefolium were separated from the 
Linnaean Potentilla with Pentaphyllum (or Quinquefolium) reptans 
(Potentilla ,aptans Linn.| by numerous authors before 1778. If 
the author feels that it is necessary to accept Argentina because 
segregated first leaving the other plant in possession of the name 
2 Mem. Dept. Bot. Columbia Univ. Vol. II. p. 2. Monograph N. Am. 
Potentill. (1898.) 
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