PIPER FLORA OF THE STATE OF WASHINGTON. 553 



Pappus never capillary. 



Receptacle chaffy IIeliantheae. 



Receptacle not chaffy IIelenieae. 



Pappus capillary Senecioneae. 



Involucre scarious, pappus not capillary Antiiemideae. 



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

 heads not radiate. 



Receptacle not bristly; corollas not deeply cleft Inuleae. 



Receptacle long bristly; corollas deeply cleft Cynaheae. 



EUPATORIEAE. 



Akoiios r)-angled Eupatorium (p. r)55) . 



Akenes l()-ril)i)cd Coleosanthus (p. 5.50) . 



ASTERExVE. 



Pappus of 2 to 8 rigid awns; heads large, gummy Grindelia (p. 550). 



Pappus of nimierous capillary bristles. 

 Rays yellow (sometimes wanting). 



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



Pappus simple. 



Heads rayless, small, clustered Ciirysothamnus (p. 55S) . 



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 .. Hoorebekia (p. 559). 

 Pappus t)ristles eqlial; heads small, clus- 

 tered. 



Panicle thyrsoid; receptacle alveolate.. Soi,ida(;o (p. 5()1). 

 Panicle flat-topped; receptacle fimbril- 



late EuTiiAMiA (p. 503) . 



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

 rarely wanting. 



Pappus a single series of coarse, rigid bristles Townsendia (p. 503). 



Pappus of numerous soft bristles. 



Bracts of the involucre in many seiios, their 



tips spreading Machaeranthera (p. 575) . 



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

 their tips niostl}' erect. 



Involucral bracts in one or two series, nur- 



row; rays usually narrow and numerous . Kriceron (p. 503). 

 Involucral bracts in two to five series, 

 rays broader, less numerous. 



Involucre narrow, with rigid bracts; 



rays white, few SERicorARRUs (p. 509). 



Involucre turbinate or hemispheric. 



Stems scape-like Oreastrum (p. 5(i9). 



Stems leafy. 



Scales of the involucre dry 

 and chartaceous, closely 



appressed Eucephalus (p. 509). 



Scales of the involucre more 

 or less herbaceous and 

 .spreading Aster (p. 570). 



