6 PREFACE. 



structure. There is, I believe, no sufficient work of this kind in the 

 English language, adapted to our needs, and available even to our 

 botanists and botanical teachers — for whom the only resource is to a 

 botanical library beyond the reach and means of most of these, and 

 certainly quite beyond the reach of those whose needs I have here 

 endeavored to supply, so far as I could, in this small volume. The 

 great difficulties of the undertaking have been to keep the book within 

 the proper compass, by a rigid exclusion of all extraneous and unneces- 

 sary matter, and to determine what plants, both native and exotic, are 

 common enough to demand a place in it, or so uncommon that they 

 may be omitted. It is very unlikely that I can have chosen wisely in 

 all cases and for all parts of the country, and in view of the different 

 requirements of botanical students on the one hand and of practical 

 cultivators on the other — the latter commonly caring more for 

 made varieties, races and crosses, than for species, which are the 

 main objects of botanical study. 



But I have here brought together, within less than 350 pages, brief 

 and plain botanical descriptions or notices of 2650 species, belonging 

 to 947 genera ; and have constructed keys to the natural families, and 

 analyses of their contents, which I hope may enable students, who 

 have well studied the First Lessons, to find out the name, main char- 

 acters, and place of any of them which they will patiently examine in 

 blossom, and, when practicable, in fruit also. If the book answers 

 its purpose reasonably well, its shortcomings as regards cultivated 

 plants may be made up hereafter. As to the native plants omitted, 

 they are to be found, and may best be studied, in the Manual of the 

 Botany of the Northern United States, and in Chapman's Flora of the 

 Southern United States. 



This book is designed to be the companion of the First Lessons in 

 Botany, which serves as grammar and dictionary ; and the two may 

 be bound together into one compact volume, forming a comprehensive 

 School Botany. 



For the account of the Ferns, and the allied families of Cryptoga- 

 mous Plants I have to record my indebtedness to Professor D. C. 

 Eaton of Yale College. These beautiful plants are now much cul- 

 tivated by amateurs; and the means here so fully provided for 

 studying them will doubtless be appreciated. 



Harvard University Herbarium, Cambridge, Mass., 

 August 29, 1868. 



