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O15 OCT 1892 Given by Dr. 7. Britten HBF 

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PREFACE. 
In the following pages there has been no attempt made at 
original work. On the contrary, the standard writings of Gray, 
Engelmann, Chapman, De Candolle, Parlatore, Andersson, 
Loudon, and Gordon have been freely used. It is hoped that 
the names given will be found correct. It is, however, fair to 
say that in some instances it was not deemed wise to adopt the 
latest nomenclature, because, first, it is not yet accepted by 
the garden authorities or recognized by amateur botanists, and 
hence might confuse rather than aid; and, secondly, there is no 
authoritative manual accessible in which they are so accepted. 
This reserve, then, is to be considered in the interest of prudence 
and not of exact science. 
The alphabetical arrangement of orders, genera, and species 
is a sin against botanical law, but appears to be demanded by the 
needs of the Park. 
The number of synonymes quoted has not been from choice, 
but for the obvious purpose of aiding in the recognition of a 
species under its most common disguises of name. It is the 
more a matter of regret, as it has often caused the exclusion of 
statements and descriptions of greater general interest. The 
star (*) means that the plants opposite are yet desired. 
PHILADELPHIA, March, 1880. 
143064 
