INTRODUCTION 
xix 
After the description of the subspecific forms, the distribution (in the larger type) of the species 
as a whole completes the account of the species. Thus, each subspecific form is enclosed within 
the species of which it forms a part. The distribution is stated in two paragraphs, the first relating 
to the distribution of the plant within the British Isles, and the second to its distribution abroad. 
Hybrids 
Hybrids are not given a central heading; but the name of each hybrid is printed in thick 
special type ; and the name is followed by synonymy, description, and distribution (this being again 
in the smaller type), in the manner of the other groups as above explained. Hybrid-forms are 
printed in smaller special type, and are preceded by a capital letter. 
Common names of plants 
The common names of plants are given in the central heading of the species, and on the 
plates ; but it has not been thought worth while to insert “ common ” names for all species nor 
to use “common” names invented in recent years by other botanists. For example, we do not 
see that any useful purpose is served by naming Scirpus pauciflorus “the few-flowered spike-rush.” 
The botanist who is interested in the study of this plant is content to name it Scirpus pauciflorus. 
Common names which are of local or limited use are not given. These vernacular names are, we 
need scarcely state, of very great interest ; but they form a special study, and, on the whole, are 
out of place in a flora of a national character. 
Maps showing distribution 
In certain cases, maps are given showing the British distribution of species. It is, of course, 
unnecessary to furnish such maps of species which occur throughout the length and breadth of 
the British Islands, and of species whose occurrence is limited to a single county. In other cases, 
particularly in the cases of trees 1 , the available records have not been found to be very useful 
in enabling us to decide the natural geographical limits of species ; and maps therefore cannot 
be furnished of these species. Further, the published records of a considerable number of critical 
species are more or less unreliable ; and in these cases it is unwise to furnish any map. 
All the maps used in this work have the same scale. They are divided into counties by 
thin dotted lines, and into groups of counties by thicker dotted lines. In a few cases where 
the counties are unduly large and specially interesting from a phytogeographical point of view, 
subdivisions of the counties have been indicated ; e.g., Yorkshire, Perthshire, Argyllshire, Inver- 
ness-shire, and co. Galway. Little or no attempt is made to indicate local distribution within 
the limits of the counties or the subcomital divisions. 
Distribution 
The following sources of information have been drawn upon in ascertaining the distribution of 
the species within the limits of the British Islands : — 
Topographical Botany ed. 2 (1883), by H. C. Watson. In this work, county records are given of the plants 
of Great Britain. 
Supplement to Topographical Botany ed. 2, by Arthur Bennett; in The Journal of Botany xliii (1905). This 
gives the additional records of the plants (except Salix) of Great Britain made up to 1903. For records later 
than this, we have often been indebted to Mr A. Bennett for supplying us with information. 
•• Irish Topographical Botany , by R. Lloyd Praeger; in Proc. Roy. Irish Acad. ser. 3, vol. vii ; and also 
Dublin (1901). Later Irish records by Mr Praeger are to be found in the Proc. Roy. Irish Acad, xxvi, B, 13 — 
45 (1906), and in The Irish Naturalist xvii, 28 — 37 (1908) and xxii, 103 — no (1913). 
Additions and Corrections to the Topographical Botany of Scotland , by Professor James W. H. Traill, in Annals 
of Scottish Natural History for 1905 and following years. 
In addition, articles frequently appear in The Journal of Botany and elsewhere giving new particulars 
of local distribution ; and these have been utilised to some extent. However, we have, for various reasons, not 
taken all these records at their face-value. 
1 The point of view which we adopt in relation to the indigenousness of trees has been stated in an article on “The 
Woodlands of England,” by C. E. Moss, W. M. Rankin, and A. G. Tansley, in The New Phytologist , ix, pp. 113 — 149 
(1910); also published separately by the British Ecological Society, London. 
