SCIENTIFIC PAPERS. 
SYNOPSIS OF THE GENUS LONICERA. 
BY ALFRED REHDER. 
INTRODUCTION. 
The last general review of the genus Lonicera was pub- 
lished more than seventy years ago by A. P. De Candolle 
in the fourth volume of his Prodromus, where 53 species 
are enumerated of which, however, one is inserted twice, 
one does not belong to the genus and nine are now 
referred to other species as varieties or synonyms. This 
leaves only 42 recognized species. Since that time 
this number has more than tripled, chiefly from discover- 
ies made in central and eastern Asia, so that now there are 
known more than 150 well distinguished species. 
As the literature and references to these species are 
widely scattered through numerous books and periodicals, 
it is at present rather difficult to properly place and 
determine unknown species, particularly those of Asiatic 
origin, though the difficulty is somewhat relieved by more 
or less comprehensive accounts of the species of certain 
regions, as given by Maximowicz, Regel, Clarke, Franchet, 
Gray, Wolf, and by systematic enumerations of the culti- 
vated species published by Koch, Dippel and Koehne, 
In looking over the literature of the genus one cannot. 
help noticing the great diversity of opinion exhibited by 
the different writers as regards the limitation of the divi- 
sions and subdivisions of the genus. This is not because 
the distinctive characters are obscure and slight; on the 
contrary, there is a great variety of obvious characters, 
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