The Distribution of certain Portions of the British 
Flora. 
I. Plants restricted to England and Wales. 
BY 
J. R. MATTHEWS, M.A., F.F.S., 
Royal Botanic Garden, Edinburgh. 
With six Diagrams in the Text. 
Introductory. 
T HE flora of the British Isles, although a comparatively limited one, 
presents many interesting problems in plant-geography. These 
problems, as is well known, have been discussed from time to time, especially 
since Edward Forbes ( 1846 ) dealt with them in a classic memoir, ‘ On the 
Connexion between the Distribution of the existing Fauna and Flora of the 
British Isles and the Geological Changes which have affected their Area \ 
Forbes, an advocate of overland migration, recognized five distinct sub¬ 
floras and explained their distribution in Britain as a result of successive inva¬ 
sions from the extensive land mass lying eastward, prior to the detachment 
of Britain from the European mainland. The composition of our flora was 
also the subject of prolonged study by H. C. Watson ( 1835 , 1847 ), and 
largely to his labours, too, we owe a careful analysis of the distribution of 
our native plants as presented in ‘ Topographical Botany ’ ( 1883 ). Some of 
the ‘types of distribution’ formulated by Watson have been discussed and 
defined with greater precision in an interesting paper by Stapf ( 1914 ), while 
Moss ( 1914 ), in a general account of plant distribution in Britain, brings the 
work of Forbes and Watson into line with that of recent authors. 
All writers on the subject are generally agreed that the British flora is 
essentially a reduced continental flora, derived from the Continent in relation 
to past climatic changes, yet there is no unanimous opinion regarding the 
time and method of arrival of its several elements. A decisive answer 
cannot easily be given to these questions, for the historical succession is 
incomplete. A glance at the position, however, may not be without 
interest. 
[Annals of Botany, Vol. XXXVII. No. CXLVI. April, 1923.] 
