Carduaceae 285 



Scales of the involucre dry, papery and ap- 



pressed. Bucephalus. 



Scales of the involucre more or less herbaceous, 



and spreading. Aster. 



Style branches of the perfect flowers straight edged 



or with hairy tips. 

 Involucre not scarious. 



Pappus never capillary; receptacle chaffy or 



bristly. 

 Receptacle conic, chaffy; pappus none. 



Rudbeckia. 



Receptacle flat, chaffy ; tall herbs ; pappus 2 



scales. Helianthus. 



Receptacle bristly; pappus a crown of scales. 



Gaillardia. 

 Pappus capillary. 



Leaves all or mostly opposite. Arnica. 



Leaves alternate. 



Flowers white or pinkish ; leaves large. 



Petasites. 



Flowers yellow, leaves small. Senecio. 

 Involucre scarious. 



Receptacle chaffy; rays short. Achillea. 



Receptacle naked ; rays conspicuous. 



Chrysanthemum . 



Receptacle naked; rays none. Artemisia. 



Anthers with tails at the base; heads without rays. 

 Receptacle not bristly; corolla not deeply cleft. 

 Pappus hair-like % in pistillate flowers; club shaped 

 in staminate. Antennaria. 



Pappus of all the flowers similar. Anaphalis. 



Receptacle long bristly; corolla deeply cleft. 



Leaves and usually the involucral bracts prickly. 



Carduus. 

 Leaves and involucral bracts not prickly. 



Saussurea. 



