PREFACE. 



THE Class-Book of Botany was first offered to tlio student in 1845. 

 It was originally prepared with immediate reference to the wants of 

 the author's own pupils, with scarcely a hope of approval from the 

 community beyond. The event, however, proved that the wants of his 

 own pupils were precisely the same as those of myriads of others j and 

 the use of the book, notwithstanding its numerous imperfections, soon 

 became general. 



The lapse of fifteen years has done much to develop not only the 

 knowledge of our native Flora, but of the science of Botany in general; 

 and materials for the revision of our whole work have indefinitely 

 accumulated. In this revision, which seems to be demanded not less 

 by the growing appreciation of scientific studies as a means of intel- 

 lectual and moral discipline, than by the progress of the science itself 

 we have still confined ourselves to the limits of a single volume, and 

 sternly resolved against any essential enlargement, except such as the 

 increased territory of our Flora requires. This we have done with 

 direct reference to the convenience and the means of the thousands of 

 youths who will still enter upon this delightful pursuit, and make their 

 text-book their vade-mecum. The labor expended in this condensation 

 will be appreciated by few, and those few, while they justify the mo- 

 tives, will regret the necessity. 



The limit of our Flora in this new series has been much extended. 

 It now embraces the territory lying East of 'the Mississippi River with 

 the exception of the Southern Peninsula of Florida, and South of the 

 Great Lakes and the River St. Lawrence. The States bordering upon 

 the western shores of the Mississippi, although not strictly included, 

 are essentially so, as well as those provinces of Cawada upon the north- 

 ern shore of the St. Lawrence. This Class-Book is, therefore, now 

 professedly adapted to the student's use from Quebec to New Orleans 

 and from St. Paul to St. Augustine. 



The southern peninsula of Florida is neglected in consequence of 

 the author's inability to visit that region hitherto. During his extended 

 tour southward in 1857, the Seminole war rendered the route to the 



