PAET III. 



KEY, CLASSIFICATION AND DESCRIPTION 

 OF THE SPECIES. 



Method of Using the Key. 



FRST read all the statements following the stars (*) 

 at the beginning of the Key; decide which one of 

 the statements "best suits the specimen you have. At the 

 end of the chosen one there is a letter in parenthesis ( ). 

 Somewhere below, this letter is used two or more times. 

 Read carefully all the statements following this letter; 

 at the end of the one which most nearly states the facts 

 about your specimen, you will again be directed by a let- 

 ter to another part of the Key. Continue this process till, 

 instead of a letter, there is a number and name. The 

 name is that of the genus, and forms the first part of the 

 scientific name of the plant. Turn to the descriptive part 

 of the book, where this number, in regular order, is found. 

 Here descriptions of the species of the genus are given. 

 If there are many species, another Key will lead to the 

 species. While the illustrations are intended to represent 

 characteristic specimens, too much dependence must not 

 be placed upon them ; the leaves even of the same plant 

 vary considerably, and the different varieties, especially 

 of a cultivated plant, vary widely. Read the whole de- 

 scription before deciding. 



The fractions beside the figures indicate the scale of the 

 drawing as compared with the natural size of the part : 

 | indicates natural size ; f , that the drawing is twice the 

 length of the object ; , that the drawing is one fourth the 

 length of the object, etc. 



