IV 
PREFACE. 
devoted to this will not be the least valuable to the student of 
nature. 
The manner in w r hich the object has been accomplished it is neces- 
sary to explain more fully. And, first, as to the illustrative plates — 
they are small, for the sake of economy, and are intended chiefly to 
indicate the habit of the plants, while the magnified parts show their 
detail. They might have been finer as works of art ; but, had they 
been executed by an engraver, minute as they are, they would perhaps 
have been less botanically accurate, as the smallest variation in many 
of them would have materially altered their character; and, there- 
fore, although a first and an untutored attempt at etching, I have 
preferred executing them myself, especially as by so doing I should 
save a large expense, perhaps not be refunded by the sale of the 
work. The engravings of genera are a new feature in illustration, 
and it is hoped a useful one. 
In the record and detail of species the following order is observed : 
First, the Latin and English name, and reference to figure. Secondly, 
those essential characters which alone are necessaryfor discriminating 
the species, and which alone the true botanist will find it convenient 
to consult. The synonymes and references to figures in other works, 
which follow, give a history of the plant, and enable the student to 
refer elsewhere, if in doubt. The description may be considered 
collateral evidence, while the remaining parts will show him the 
varieties to which his plant is subject, the cause of them, its 
particular and general distribution, and the peculiarities attached 
to it. 
In the pait of the work which treats of the genera, the reader will 
find, first, the derivation of the genus, and a concise account of its 
general characteristics, and under it the arrangement of the species, 
according to their obvious distinctions. 
In the essential characters of the different species, as few words 
as possible have been used, and those few pure and scientific. In 
the synonymes, which go back to the time of Linnoeus (or in some few 
instances a little before), the names ol authors only arc given, unless 
they have called a plant by different names in different of their works, 
when the works themselves are also specified. In the descriptive 
part, and discriminating remarks which follow it, pure scientific detail 
has not been so much aimed at as obvious differences and popular 
