All such plants are included in this book as have been observed by the writer 

 as trees, even if usually occurring as shrubs. To the many species of trees already 

 known the writer has added 1 new genus, 22 new species, 31 new varieties, 3 new 

 forms and 1 new hybrid, which are all described by him. A number of new 

 species were discovered by the writer, but described by various authorities, in- 

 cluding 4 new species of Palms by O. Beccari of Florence, Italy, all of which 

 are included in this book. In an addendum the writer describes seven new 

 species, seven new varieties and one new form belonging to the Family Cam- 

 panulaceae, tribe Lobelioideae. This brings the total number of new plants 

 described by him herein up to seventy -two. 



It was also necessary in some instances to make a few new combinations. 



Of the 215 photographs nearly all were taken by the writer in the field, with 

 the exception of plates 1, 12, 17, 27, 68, 130, and 131, by Mr. R. S. Hosmer; nos. 

 29 and 37 by Mr. R. Perkins ; no. 2, by Mr. A. Gartley, and nos. 23, 26 and 31, by 

 Mr. R. J. Baker, to all of whom the writer wishes to acknowledge his indebtedness. 



The present volume is primarily due to the enthusiasm of Ex-Governor George 

 R. Carter, who headed the list of patrons and secured the necessary funds to 

 insure publication. Credit is due the College of Hawaii for supplying photo- 

 graphic material and part of the writer's time. 



It should be stated here that most of the material on which this publication 

 is based was collected by the writer under the auspices of the Board of Commis- 

 sioners of Agriculture and Forestry of this Territory. 



To Dr. H. L. Lyon the writer is indebted for technical advice, and to Dr. E. 

 Hackel and Rev. George Kiikenthal for identification of Grasses and Cyperaceae 

 respectively. 



To Mr. Francis Gay of Kauai the writer is greatly indebted for knowledge of 

 matters pertaining to Hawaiian names of trees and their vises ; he also wishes to 

 express his thanks to all those who extended to him the far-famed Hawaiian 

 hospitality during his many sojourns on the various islands of the group. 



Last but not least the writer wishes to acknowledge the kind assistance of 

 Prof. H. M. Ballon of the College of Hawaii in his painstaking reading of proof- 

 sheets, and expresses his thanks to him and all those who have helped in the 

 preparation of this book. 



The volume is herewith presented to the public, who the writer hopes will be 

 lenient towards any mistakes in the construction of sentences, English not being 

 his mother-tongue. 



JOSEPH F. ROCK. 

 College of Hawaii, 

 Honolulu. T. H., April 23, 1913. 



