PREFACE. 
IX 
is distinguished. Those who desire a more particular acquaint¬ 
ance with the structure, and especially the physiology of plants, 
may be referred to the author’s Botanical Text-Book (second edi¬ 
tion), or other detailed elementary works. 
An artificial analysis of the Natural Orders or Families, found¬ 
ed on the easier and chiefly external characters, is appended, to 
aid the learner at the point where he is likely most to need assist¬ 
ance, namely, in referring an unknown plant to its proper order. 
Every successful attempt, however, will give him new power; 
and the thorough study, by this system, of half a dozen plants of 
different families will give more knowledge and insight into the 
science than can be acquired by ascertaining the names (which 
is nearly all that is done) of a hundred species by means of a 
facile, thought-saving, artificial classification. Still, as some ar¬ 
tificial analysis which leads directly to the genera is a great con¬ 
venience to the student in cases of difficulty, I have added a full 
Conspectus of the genera comprised in this work, reduced to the 
Classes and Orders of the Linnaean Artificial System, so generally 
in use until recently. The plan upon which this is constructed 
will be found to possess some advantages over an ordinary Lin- 
mean arrangement, inasmuch as it provides for the exceptional 
cases, where different species of a genus actually present the 
characters of different artificial classes. 
I am under very great obligation to my excellent friend, John 
Carey, Esq., for important assistance rendered throughout the 
progress of this work, and especially for the elaboration of the 
Willows , Poplars , and the vast and difficult genus Carex , which 
are wholly from his hand. I am equally indebted to my esteemed 
friend, Mr Stjllivant, for the entire elaboration of the Orders 
Musci and Hepatic #, which he has for a long time made the sub¬ 
ject of special study and illustration. Through his labors, it may 
