8 PKBFACB 



demonstrated. In a few instances, however, it has been impossible 

 from lack of material or data either to include as valid or to reduce 

 definitely to synonymy such species and varieties, and it has accord- 

 ingly seemed best not to mention them. It is not thereby meant 

 that they are not of value, but merely that evidence of their distinct- 

 ness has not been available. 



Botanical names, being in many instances latinized forms of 

 geographic, aboriginal, or personal designations, are not always 

 capable of easy or consistent pronunciation. From long-established 

 custom they are usually pronounced in English-speaking countries 

 according to the pronunciation of Latin after the English method, 

 exceptions being frequent in such names as Michauxiana, which is 

 commonly pronounced mesholana, or by others meshoziana, to avoid 

 the awkward pronunciation which the word would have according 

 to the English rules. The subject is one into which considerations 

 of taste, convenience, and custom enter to such an extent that it is 

 most difficult to lay down definite principles free from pedantry. 

 However, as a general guide, the names in this, as in previous edi- 

 tions, are marked with accents, — the accented syllable being deter- 

 mined as far as possible by the well-known rules of Latin quantity. 

 In cases of doubtful quantity, in such names as Berlandiera, Palmeri, 

 Bacopa, etc., it has seemed best to treat the penultimate vowel as 

 long, according to the usage of most British and Continental writers. 

 Two accents are used, the grave (') to indicate the long English 

 sound of the vowel, the acute (') to show the shortened or other- 

 wise modified sound. Eor aid in determining the accented syllable, 

 the editors are in several instances indebted to Dr. A. S. Pease. 



In consideration of recent differences m nomenclatorial practice, 

 and with a wish to make the Manual as convenient as possible for 

 all users, synonyms have been inserted freely to show the equiva- 

 lence of diiferent names, especially of those permitted by the 

 Uoohester and American Codes but not sanctioned by the Interna- 

 tional Rules. It has been necessary to make these citations exceed- 

 ingly brief, the specific name, when the same, being omitted; e.g. 

 under Ranunculus Gymhalaria Pursh, the synonym OxygrapMs Prantl 

 means that the species has been treated by Prantl under the identi- 

 cal specific name {Gymhalaria) in Oxygraphis, a genus not maintained 

 in the present work. 



B. L. R. 

 M. L. F. 



