INTRODUCTION 



"II. Petals absent", being impossible. The next choice is "i. Flowers 

 single or in clusters", not "2. Flowers in heads", as in the dandelion 

 or the clover. The united petals lead one past "a. Petals separate" 

 to "b. Petals united", and then one goes successively to "(1) Ovary 

 superior", "(a) Flowers regular", and "x. Stamens 2". The family 

 is consequently the olive family, O 1 e a c e a e, to be found on page 



V. Lobed Simple Leaves. 



Pinnately: 

 Palmately: 



5. Parted. 



6. Parted. 



7. Divided 



8. Divided. 



107. Here the family description should first be checked over, and 

 then the genus of the lilac is sought in the "Key to the Genera". The 

 choice between "1" and "2" falls readily upon the latter and beneath 

 "2", first upon "a", and then upon "(1) Flowers purple . 

 Syringa". After checking over the description of the latter upon 

 page in, the common lilac is found to be Syringa vulgaris by 

 means of the "Key to the Species". It is described on page 112 and 

 figured on page 114. 



In the case of the cottonwood, the small flowers of the hanging 

 catkins, which are of two kinds, reddish brown on one tree and green- 

 ish on the cotton-bearing tree, are seen to lack both petals and sepals. 

 Hence, under "II. Petals absent", the choice is "2. Sepals absent, 

 or occasionally very minute". The next choice is "b. Leaves not 

 scale-like or needle-like, deciduous", and after this, "(1) Leaves 

 simple". Under this, the ovate leaves lead to "(b)" and the cottony 

 seeds to "(x) . . . Salicaceae", or willow family, page 53. Here 



