PIPER FLORA OP THE STATE OP WASHINGTON. 553 



Pappus never capillary. 



Receptacle chaffy Heliantheae. 



Receptacle not chaffy Helenieae. 



Pappus capillary Senecioneae. 



Involucre scarious, pappus not capillary Anthemideae. 



Anthers caudate at base; style-branches neither truncate nor appendaged; 

 heads not radiate. 



Receptacle not bristly; corollas not deeply cleft Inuleae. 



Receptacle long bristly; corollas deeply cleft Cynareae. 



EUPATORIEAE. 



Akenes 5-angled Eupatorium (p. 555) . 



Akenes 10-ribbed Coleosanthus (p. 556) . 



ASTEREAE. 



Pappus of 2 to 8 rigid awns; heads large, gummy Grindelia (p. 556). 



Pappus of numerous capillary bristles. 

 Rays yellow (sometimes wanting). 



Pappus double, the outer very short Chrysopsis (p. 557) . 



Pappus simple. 



Heads rayless, small, clustered Ciirysothamnus (p. 558) . 



Heads radiate or if rayless, large. 



Pappus bristles unequal; heads mostly few 

 and large. 



Style branches setaceous-tipped Ericameria (p. 559) . 



Style branches not setaceous-tipped .. IIoorebekia (p. 559). 

 Pappus bristles equal; heads small, clus- 

 tered. 



Panicle thy rsoid; receptacle alveolate. . Solidago (p. 561). 

 Panicle flat-topped; receptacle fimbril- 



late EuTHAMiA (p. 563). 



Rays white, purple, or blue (yellow in a few Erigcrons), 

 rarely wanting. 



Pappus a single series of coarse, rigid bristles Townsendia (p. 563). 



Pappus of numerous soft bristles. 



Bracts of the involucre in many series, their 



tips spreading Machaeranthkra (p. 575). 



Bracts of the involucre in few (1 to 5) series, 

 their tips mostly erect. 



Involucral bracts in one or two series, nar- 

 row; rays usually narrow and numerous . Erigeuon (p. 563). 

 Involucral bracts in two to five series, 

 rays broader, less numerous. 



Involucre narrow, with rigid bracts; 



rays white, few Sericocarpus (p. 569). 



Involucre turbinate or hemispheric. 



Stems scape-like Oreastrum (p. 569). 



Stems leafy. 



Scales of the involucre dry 

 and chartaceous, closely 



appressed Eucephalus (p. 569). 



Scales of the involucre more 



or less herbaceous and , / 



spreading , Aster (p. 570). 



