244 ASTER ORDER 



(1) Heads large, rose-purple to cream-colored, 



usually with spiny bracts; leaves spiny; 



pappus hairy CARDUUS 



(2) Heads not large or spiny; leaves rarely 



spiny 



(a) Flowers red or purple 



x. Leaves in whorls of 3-5 EUPATORIUM 



y. Leaves alternate 



(x) Heads in spikes or racemes LACINIARIA 



(y) Heads in flat-topped panicles VERNONIA 



(b) Flowers yellow, cream-colored or white 

 x. Pappus hairy 



(x) Receptacle with chaffy scales among 



the flowers FILAGO 



(y) Receptacle without chaff 

 m. Shrubs 



(m) Heads dioecious BACCHARIS 



(n) Heads perfect TETRADYMIA 



n. Herbs 



(m) Heads white 



r. Leaves large and arrow-shaped PETASITES 

 s. Leaves not large and arrow- 

 shaped 

 (r) Leaves opposite; involucre 



and leaves not woolly EUPATORIUM 

 (s) Leaves alternate or basal; 

 involucre and leaves 

 more or less woolly 

 h. Heads dioecious 



(h) Stems mostly low, with 



basal leaves ANTENNARIA 



(i) Stems tall and leafy ANAPHALIS 

 i. Heads monoecious GNAPHALIUM 



(n) Heads cream-colored, yellow or 



. yellowish 

 r. Flowers cream-colored 



(r) Leaves more or less oppo- 

 site ; involucre bell- 

 shaped COLEANTHUS 

 (s) Leaves alternate ; involucre 



oblong KUHNIA 



