PREFACE. v 
The writer now has the great pleasure of recording his obligations and thanks to 
Mr. W. H. Fitch, the artist, and to his colleagues at Kew, especially to Professor D. 
Oliver, whose unrivalled knowledge of flowering plants is always at the service of 
others. Mr. J. G. Baker is almost wholly responsible for the nomenclature and 
limitation of the species of vascular cryptogams; but this matter is more fully 
explained in the remarks under the various orders. 
The writer also feels that he would very much like to be permitted to. mention 
that he has experienced the most liberal treatment from the Editors, who have expended 
a much larger sum of money (to say nothing of time) on the work than they can 
possibly see returned. Under other circumstances much more might be written on 
this point. 
The coloured Plates were taken from sketches made from the fresh plants by 
Mrs. Salvin in Central America in 1873-74. 
WILLIAM BOTTING HEMSLEY. 
Chiswick, October 1888. | 
