4 
EXPLANATIONS OF THE CATALOGUE. 
subsequent editions always referred to the same trouble, till in the fifth edition no 
less than three separate lists of “ Excluded Species” were published, and not until 
the publication of the eighth edition was the plan of having separate lists wholly 
dropped. It has been the aim of those who have compiled the Catalogue to adopt 
as reasonable a course as possible on this subject, though their efforts in this 
direction cannot be expected to please everyone. 
* implies that a plant is cither most probably or certainly not aboriginal 
(native), but more or less well established. 
[ ] is used in two senses (1) when the type of a species does not occur in 
Britain ; and (2) when a species or variety appears to have become extinct. 
() usually means that the author cited described the plant as a species ; or 
otherwise encloses the synonyms which have been added. 
/. denotes “forma" or “ sub-varietas," and is not unfrequently employed 
where the original author considered the plant to be a good variety or even 
a species. 
X denotes a hybrid. 
Italics denote a casual or only planted alien, apparently not yet naturalized. 
Obviously, the line between such and those marked with a * cannot be drawn 
quite accuratelv, but each case has been carefully considered. A considerable 
number of species allowed to pass without a * are more or less doubtfully native, 
but have been allowed the benefit of the doubt. 
The numerals following each species refer to the 112 vice-counties into which 
Great Britain was divided by H. C. Watson in Topographical Botany. 
“1” refers to species found in Ireland only; “C" to species found in the 
Channel Islands only. 
It may be well to state once more that the Catalogue is not intended to be a 
critical authority as to which plants are to be considered as species, sub-species, 
varieties and forms, which is the proper function of a Flora ; but aims simply at 
providing in the most convenient form, a useful working lisl of British Plants. It 
shows at a glance the relative frequency of the various species, and may be used 
as an index catalogue to the herbarium, for purposes of exchange and for making 
local lists ; it follows no one Flora, but seeks to embody the most generally 
accepted opinions of British botanists. It aims, in short, at utility rather than 
authority; although no pains have been spared to make it as accurate as possible 
for the purposes for which it exists. 
- The following explanation of the use of the census numbers is extracted from 
Mr. Watson's “Explanations” in the Seventh Edition of the Catalogue. 
“The numbers which follow the names of plants are intended for a census— 
a scale of rarity or frequency in relation to Britain as a whole. They express the 
numbers of counties in which the species has been reported to occur, as set forth 
in [the 2nd edition of] Topographical Botany [revised as before stated]. By sub¬ 
dividing the larger counties into two or more vice-counties, as explained in the 
work mentioned, their number is increased to 112. Various circumstances interfere 
with the possibility of making these numbers quite exact, either absolutely so or in 
comparison with each other ; explanations of which may be sought in the work 
from which the numbers are taken. In general, these numbers show the counties 
ascertained for the species in a native or quasi-native condition ; but in several 
instances, notably in the instances of fruit-trees and timber-trees, of mints and 
other culinary herbs, the number has been given too high through the impossibility 
of clearly distinguishing the truly native habitats from others improperly so 
reported. In cases where an old aggregate has been divided and now appears 
under two or more segregate names, the census numbers will usually be too low, 
through want of full records in accordance with the change." 
FREDERICK J. HANBURY, 
• 37 Lombard Street, London, E.C. 3. 
And Brockhurst, East Grinstead. 
June , rqz.v 
