SIGNS AND EXPLANATIONS. 



The Signs and Abbreviations employed in this work are few. The 

 signs are : — 



® for an annual plant. 

 @ for a biennial plant. 

 "U for a perennial plant. 



The signs for degrees, minutes, and seconds are used for feet, inches, 

 and lines, the latter twelve to the inch. Thus 1° means a foot in length 

 or height, &c. ; 2', two inches ; 6", five lines, or five-twelfths of an inch. 



The dash between two figures, as 5- 10 means from five to ten, &c. 



The character oo means many. 



El. stands for flowers or flowering. 



Cult, stands for cultivated. 



Nat. stands for naturalized. 



N., E., S., W. stand for North, East, South, and West. 



The geographical abbreviations, such as Eu. for Europe, and the com- 

 mon abbreviations for the names of the States, need no particular expla- 

 nation. 



Species printed in heavy-faced Roman type are indigenous to some 

 part of our territory (the IT. S., East of the 100th meridian). 



Those in heavy -faced Italic type are not indigenous to this territory, and 

 they exist in our region only in cultivation or as introduced weeds. 



The species and varieties in small capital Roman letters are hor- 

 ticultural forms or hybrids. When in parenthesis, they are simply 

 synonyms. 



Pronunciation. — In accordance with the usage in Gray's botanies, it 

 is intended that the Latin names in this volume shall be pronounced after 

 the English method. The accent marks designate both the accentuation 

 (or most emphatic syllable), and the length of the vowel. The grave (') 

 designates a long vowel, and the acute (') a short one. The letters oi, 

 like to, representing the Greek ending -oe(8ijs, should properly be pro- 

 nounced separately. If the i, in this case, is the penultimate syllable 

 (next to the last) , it should be pronounced long, as in prino-ides, usneo- 

 ides; but if it is the antepenultimate (third syllable from the end), it is 

 pronounced short, as rhombo-tdeq. In names derived from dioicus and 

 monoicus (dioecious and monoecious), di is a true diphthong, as in choice. 



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