KEY. 



All flowering plants fall under one of the divisions of para- 

 graph 2. The reader is there referred by the figure at the right to 

 another paragraph giving more minute specifications. Under the 

 second paragraph consulted, he will find a similar reference to a 

 third, and so on, until he reaches one containing the name of the 

 plant under examination. 



1. Plants bearing flowers, PH-SINOG-AMS 2 



Plants destitute of flowers, CRYPTOGAMS.* 



S. Several or many flowers enclosed in an involucre (an 

 apparent calyx) 3 



No calyx-like involucre to several flowers 4 



3. The anthers cohering more or less in a tube or ring, 

 which encloses the style. Flow^ers densely crowded in a head 

 on a common receptacle, surrounded by an involucre of 

 bracts (scales). Com^yosites 904 



Anthers not forming a tube or ring 4 



4. All tlie flowers on a plant, or at least several of them, 

 .furnished Avitli stamens as well as (1 or more) pistils. Per- 

 fect^ or Hermaphrodite flowers 5 



Some flowers having stamens only and no pistils; others 

 a pistil or pistils, but no stamens ; Diclinous or Separate 

 flowers 774 



5. Stamens more than 20 G 



Stamens fewer than 20 77 



6. Stamens distinct, and not in obvious clusters 7 



Stamens more or less united by their filaments, the lat- 

 ter sometimes forming a tube, or else disj^osed in clusters 

 without cohering by their filaments ^^ 



* They are not analyzed in this key. 



