PREFACE, xix 
BoRBALI-AMERICANA” as near as possible, avoiding 
carefully to change old established names, however 
faulty, unless in cases where good authority furnished a 
more appropriate one. As for example, I have adopted 
Fraxinus acuminata of Lamarck, instead of Fraxinus 
americana, Linn., and Cynoglossum amplexicaule of 
Michaux for OPtopldium virginicum, Linn. But F 
have never approved of such changes as Juglans alla 
and cinerea of Linneus to Juglans squamata and ca- 
Hee. a, Michaux in tiy iid * Arbres. ner 
long established species, and sometimes even without 
the least hint respecting their names in other authors, 
"The specific characters in most instances have been mo- 
¿lled anew or altered asit was found necessary. Where- 
ever any alteration had been made it was necessary to 
quote the author from which the species had been taken 
: ate line, as page 16 Monarda didyma ; after 
the specifie description I had to repeat that it was the 
same with M. didyma; ‘Willd. sp. pl. 1. p.125. To 
avoid this superflaous repetition, and save as much room. 
as possible, I found it expedient to adopt, from page 72 
to the end, the following mark (—), to be placed after 
the specific character whenever it had been amended ; 
so that Stipa avenacea, page 72, is the same species de- 
— ribed 5 Willd. sp. pl. 1. p. 442, but the character is 
iugmented. Wherever the author follws ‘thie 
scription without this mark, as page 72, Sacchi 
gig : mtem, fr Penson: 1. pe 109; inthate case ee 
b 2 
