COMPOSITAE (composite FAMILY) 



777 



Flowers purple 6. T^iliea. 



Flowers whitish. 

 Involucral bracts much imbricated ; leaves chiefly- 

 opposite 7. BrickeUia. 



Involucral bracts little imbricated ; leaves alternate . 78. Cacalia. 

 'A. Pappus not composed of bristles 6. 



e. Pappus none or a mere crown-like margin to the fruit. 



Heads 1-flowered, themselves aggregated into globose glomerules; 



leaves prickly 81. EcMnopB. 



Heads many-flowered ; leaves not prickly. 

 Outer involucre foliaceous; leaves opposite at least below . 88. PolymrUa. 



Outer involucre not foliaceous ; leaves alternate. 



Receptacle conical, becoming elongated 69. Matricaria. 



Receptacle flattish or merely convex. 

 Heads chiefly nodding, In spikes, racemes, or panicles , . 78. Artemieia. 



Heads corymbose 70. CJi^Banthemum 



e. Pappus present/. 

 /. Pappus composed of scales or cha£f. 

 Receptacle naked. 



Leaves in whorls . 8. Sclerolepta. 



Leaves alternate. 



Leaves dissected 61. Hym&nopappua. 



Leaves entire 62. Polypt&ria. 



Receptacle bearing chaff among tbe flowers. 



Leaves toothed or lobed 65. Oaillardia, 



Leaves entire 58. Marskallia. 



/, Pappus of 2-Eeveral teeth or awns. 



Pappus caducous 10. GrvndeUa, 



Pappus persistent. 



Achenes laterally compressed 58. Verbesina. 



Achenes terete or flattened parallel with the involucral bracts. 

 PappuR barbed. 

 Bracts of inner involucre connate to middle ; achenes terete 55. Thelesperma. 

 Bracts of Inner involucre distinct or nearly so; achenes 



obcompressed 56. Bidens. 



Pappus not barbed ... . . . 54. Coreopsis. 



* * Flowers of two kinds in the same head g. 



g. Marginal flowers neutral and sterile, either conspicuous or Inconspicuous. 



Leaves spiny ; heads subtended by foliaceous bracts . , . ,87. Gnieus. 

 Leaves not spiny ; no conspicuQUS foliaceous bracts . . , .86. C&nta/wrea. 

 g. Marginal flowers plstlflate and fertfle h. 

 7b. Receptacle chaffy. 



Receptacle awl-shaped ; achenes terete 27. Oifola. 



Receptacle flattish or moderately convex ; achenes flattened . . 51. ffeUanthus. 

 h. Receptacle naked or bearing no conspicuous chaff i, 

 i. Pappus of capillary bristles ^. 

 j. Involu^'-al bracts Imbricated in several rows. 



Leaves toothed ; not woolly 26. Pluohea. 



Leaves entire ; plant more or less woolly. 



Some flowers staminate and sterile 29. Anaphalia. 



All flowers fertile, either pistillate or perfect . . . .80. GnaphaUttm 

 j, Involucral bracts chiefly in one row. 



Leaves cordate, triangular or palmately lobed . . . . 75. Petasites, 

 Leaves not cordate. 



Involucre campanulate 28. Bh^geron. 



Involucre ovoid at base, cylindrlc above 77. ErechUtes. 



i. Pappus a short crown or none. 



Achenes becoming much longer than the involucre , . .32. Adenocaulon-. 

 Achenes not exceeding the involucre. 



Heads corymbose, erect 71. Tanacetum. 



Heads solitary on'long peduncles 72. Coiula. 



Heads racemose or paniculate, nodding. 

 Lower leaves opposite . .... .39. Isa. 



Lower leaves alternate 78. Artemisia, 



*** Staminate and pistillate flowers in separate heads k. 

 k. Pappus capillary. . 



Leaves prickly ; heads large . 88. Oirszum. 



Leaves not prickly ; heads small. 

 Shrubs ; leaves mostly toothed 25. Baccharis. 



Pappus-bristles somewhat club-shaped in sterile flowers, but capil- 

 lary and slightly connate at base in the fertile . . .28. Antennaria. 

 Pappus-bristles all icapillary, not at all connate . . , .29. AnaphaUs. 

 fc. Pappus none; fertile Involucre becoming bur-like. 



Bracts of the staminate involucre united into a cup. 

 Fertile involucre armed with one ring of spines, teeth, or blunt 



processes , . , 40. 4»i&ros^(f. 



