VI PREFACE. 



proper titles, without regard to nationalities or prejudices. 

 The author acknowledges his indebtedness to the excellent 

 works of Gray, Chapman, Darlington, Endlicher, Richard, 

 Loudon, Gordon, Lawson, Murray, Nuttall, Michaux, and 

 others, from which a portion of the descriptions have been 

 drawn. 



To the following friends, who have aided him in his 

 11 labor of love" he would return his sincere thanks, whilst 

 gratefully remembering the many acts of kindness received 

 from others, who are not particularized in this place. 



To Thomas Meehan, editor of the " Gardener's Monthly," 

 for his constant aid from the commencement of the work, 

 and especially for valuable information in regard to the 

 newer species. 



To his esteemed correspondent, Dr. C. C. Parry, of 

 Davenport, Iowa, for many interesting notes furnished on 

 our Rocky Mountain Coniferae. 



To Professors S. S. Rathvon, and J. Stauffer, of Lan- 

 caster, Pa., for valuable notes on insects injurious to this 

 family of trees. 



To Prof. George Thurber, of New York City, for his 

 careful supervision of the whole work, and by whose prac- 

 tical knowledge its value has been greatly enhanced. 



To the late John Evans, of Radnor, Pa., for many excel- 

 lent ideas, as well as for numerous specimens contributed, 

 the result of a long life of study and travel. 



To the late Dr. Wm. Darlington and Joshua Hoopes, 

 of West Chester, Pa., for unvarying kindness, unsolicited 

 assistance, and the advice and instruction which enabled 

 him to become acquainted with this important subject. 



Should this first attempt be rewarded by the encourage- 

 ment of the reader, and a renewed interest awakened even 

 in a few, the author will feel that the time devoted to its 

 compilation has been well spent. 



JOSIAH HOOPES. 



Cherry Hill Nurseries, West Chester, Pa. 



