22 VASCULAR PLANTS. 



Tribe I. Asteroideae. 



Anthers without tails. Style branches of 

 disk flowers, flat with an appendage. Leaves 

 alternate. 



a. Parts of the pappus of definite number. 

 i. Gutierrezia, Lag. 



Superflua. Heads few-flowered; ray flowers 

 about 3, ligulate; disk flowers about 5. Scales 

 of the involucre coriaceous, imbricate, their 

 tips green, reflexed. Akenes terete; pappus of 

 about 9, paleaceous scales. 



2[ . £ . flowers yellow. 



2. Grindelia, Willd. 



Superflua. iEqualis. Head cc-flowered; ray 

 flowers ligulate, 1-seriate. Scales of the hem- 

 ispherical involucre imbricate in several series, 

 their green tips squarrose. Akenes compressed; 

 pappus aristate. 



Resinous herbs; flower buds before open- 

 ing, bearing a drop of milky-looking resin. 



71 . ">? . flowers yellow. 



3. Pentachaeta, Nutt. 



Superflua. iEqualis. Ray flowers variable, 

 or altogether wanting. Scales of the involucre 

 lanceolate, scarious on the margin and tip, 

 loosely imbricate in about 2 series. Receptacle 

 convex. Pappus about 5, scabrous bristles, 



