40 coJii-osiTJ':. 



Heacls collected iuto ;i liead-lilcc chifiteY ... S^ihcemnthus. 

 2. Stvles of 2^ flowei-s inostly truncatc at the a])ex and 

 furnished with a terminal crown of liairs. 

 a. ^ flowers all sterilc. 



Pappus-set.'B deciduous connate at the Lase... 



Leontopodiiim. 



Pa})pus-seta3 free at the base Anaphalis. 



;5. ^ flowers all fertile Gnaplialmm. 



II. !^ flowers ligulate Carpcslum. 



c. Heads homogamous or lieterogamous. Style-hranches with a crowii 

 of longer hairs. Anthers rounded at tlie hase. 

 a. Pappus not hair-like. 



I. Invohicral hracts without scarious Ijhides. 



Receptacles witli ])alea3 Heliantheje. 



Corolla of -^- 0. Heads imisexual ...Xanthium. 

 Corona advanced. 

 Fruit not compressed. 



Inner involucral hracts concave emhracing 



tlic marginal fruits. Pajipus 



SiegesbecJcia. 



Inner involucral hracts flat. 



Palea very narro w Ecl ipta. 



Palea wide. 



Margin flowers -^- Wedelia. 



Margin flowers neutral Hclianthus. 



Fruit dorsally compressed. 

 * tSeta3 witli retrorse hairs. 



Leaves alternate Glossogyne. 



Leaves opposite Bidens. 



** Setas without Y(ii\-o\n(i\vA\Yii...Sijnedrella. 



Rece])tacles without palea Tagetes. 



IT. Involucral l)racts with scarious hlades at the margin 

 and apex. Pa])])us or reduced Anthemiden?. 



