356 G. Claridge Druce . 
we have called Sedum acre. Our Swiss and German confreres felt 
certain when they saw it growing in Lancashire, Westmoreland and 
Galway that it was not identical with the Continental acre. My friend 
Professor Graebner took it home and has grown it side by side in 
the Berlin garden with the German acre, and finds it differs in all its 
points. He writes “ Sedum Drucei (ined.) belongs to quite a large 
number of forms endemic in Britain which last year were observed, 
. . . and which took quite the foremost place of interest. This group 
proves beyond a doubt that the flora of the British Isles in con¬ 
sequence of the early separation from the Continent possesses a far 
larger geographical individuality, and has received a less disturbed 
development than is found in the floras of other parts of Northern 
Europe.” This statement is borne out by one’s own experience; 
one sees that the common species of Jersey have a different facies 
from those of our Midlands, while those of the north Scottish coast 
possess a distinct individuality from those of Devon or Kent. But 
it is only exceptionally that specific distinctions can be found. 
This range of variation, differing necessarily in degree, however 
suggests that we may be unwise when working with critical forms 
to attempt to identify the micro-species of Geranium, Erodium, the 
Melanium Violas and the critical species of Rosee, Euphrasies, 
Hieracia, and Taraxaci, with continental names. In many cases I 
strongly suspect that the British plants are sufficiently distinct to 
warrant them being described and named. Indeed, as will he seen, 
two of our British plants, Erigeron alpinus and Melampyrum prateuse, 
should bear, Dr. Ostenfeld suggests, other names. And if evolution 
be a fact, we might be prepared to expect these plants, living for so 
long under different climatal conditions and geographical position, 
should have evolved a facies of their own. 
With the editor’s kind permission I purpose giving a short 
resume of some additional facts which have been obtained since the 
publication of my paper, to correct a few errors, and to avail myself of 
the opportunity of thanking my foreign confreres for their very great 
kindness and assistance in answering many questions, and for the 
manner in which they received the avowedly imperfect paper which 
dealt with the botanical gatherings made during that memorable 
excursion. 
The number prefixed to the species is that given in my List of 
British Plants. When a species or variety is put in heavy type, it 
means either that it is new to the British flora or that the name is 
new. An asterisk before a name means that the plant is alien. 
The sign x means a hybrid. 
