EXPLANATORY INTRODUCTION 
TO PART II. 
This part of the book is arranged in alphabetical order, under 
Latin names. The whole of the classes, cohorts and natural orders are 
included, as well as several thousand genera, including all the British 
genera, most of the common European and American genera, and the 
chief tropical and southern genera. Hardly any important genus has 
been omitted, and even in studying such a collection as that at Kew, 
the student will find the majority of the genera treated in this work. 
The name of the genus is followed by the abbreviated name of the 
botanist who so named it, e.g. Abelia R.Br. means that Robert Brown 
was the author of this genus as thus constituted. The names adopted 
in this work are in general those given in the Index Kewensis (Oxford, 
1892-5), and a reference to that work will enable the original descrip- 
tion of the genus to be found. A list of abbreviations of authors’ names 
is given below. In several cases the name of the genus is due to a pre- 
Linnaean botanist, eg. Toumefort, and is adopted by Linnaeus; this is 
indicated thus: Acer (Tourn.) Linn. The same rules apply to the 
names of the individual species mentioned. A species has always two 
names, the generic and the specific; eg. Abies pectinata DC. means the 
species pectinata of the genus Abies , and indicates at the same time that 
this plant was so named by De Candolle. 
The use of the authority after the name of a plant is rendered 
necessary by the confusion of nomenclature that exists in Botany. The 
same species or genus often has two or more names, given to it by 
different authors or at different times. The usual rule in such cases is 
to use the name that was first applied to the plant, and to regard the 
others as synonyms', but if this rule be followed up too far, no stability 
can be assured, and it is customary therefore not to give up a long 
established name in favour of an older one that has been unearthed 
by antiquarian research. 
The study of systematic botany is rendered much more troublesome 
than it need be by the number of synonyms that exist, and the same 
cause has much increased the bulk of this work. An attempt has been 
made to include the more common and important synonyms. E.g. under 
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