Xll 
INTRODUCTION. 
membra. Between adopting this view, and holding 
them to be as many distinct species, there is little differ- 
ence ; they are distinct as far as the specific character is 
concerned ; and it is this which, no doubt, has led to 
such varieties being frequently elevated to the rank of 
species. A generic character applies to not one only, but 
includes all the species referred to that genus ; and a 
specific character, in the same way, ought to apply, 
without preference, to all the forms which, combined, 
constitute the typical species, and not to var. a. alone. 
In the present edition, therefore, we have endeavoured 
(unless, perhaps, in a few instances accidentally over- 
looked) either to extend the specific character, or to ex- 
clude from it those portions which are not common to 
all the varieties, making use of these to distinguish the 
varieties themselves from each other ; this frequently 
tends to destroy the supposed distinction between the 
aggregate species and its allies, but will better enable 
our readers to see the slender grounds on which many 
are still retained by Botanical writers. 
The design of this work would not allow of so many 
stations being given for the rarer plants as could have 
been wished ; and, indeed, the Authors have been rather 
anxious to indicate the range of the species, than the 
precise spot where any particular one is found. The 
Botanist's Guide of Messrs. Turner and Dillwyn, Mr. 
H. C. Watson’s Remarks on the Geographical Distribu- 
tion of British Plants, his New Botanist's Guide, and 
particularly his Cybele Britannica, Dr. T. Mackay’s 
Flora Hibernica, and the various local Floras and cata- 
logues of species, may, for information on this head, be 
consulted with great advantage. 
Several species were introduced by the late Sir J. E. 
Smith, not only into his Flora Britannica, but also into 
English Botany and the English Flora, which are uni- 
