776 COMPOSITAE (COMPOSITE FAMILY) 



* * * * Pappus composed entirely of capillary bristles, not plumose. 

 +- Achenes strongly ihuricate or spinulose above. 



97. Chondrilla. Stem branching, leafy. Involucre few-flowered, calyculate. Achenes terete, 



several-ribbed. 



98. Taraxacum. Scapose. Involucre calyculate, many-flowered. Achenes fusiform, 4-5-ribbed. 



+- +- Achenes not murlcate above. 



M- Achenes flat or flattish. Pappus white, fine and soft. Involucre imbricated. Leafy-stemmed, 

 with panicled heads. 



99. Sonchus. Achenes flattish, not at all beaked. Flowers 50 or more in each head, yellow. 



100. Lactuca. Achenes usually more or less beaked. Flowers 6-30 in each head, yellow, blue, 



or purple. 



H- -n- Achenes columnar, often slender. 



= Achenes not conspicuously narrowed at base. Flowers rose or purple. 



101. Lygodesmia. Achenes long, slightly tapering above. Pappus white. Steins nearly leafless ; 



Head erect. Western. 



-= = Achenes narrowed at base. 

 a. Achenes beaked (sometimes beakless in no. 102); flowers yellow. 



102. Agoseris. Scapose. Involucre loosely imbricated. Achenes 10-ribbed. 

 108. Pyrrhopappus. Scapose or branched. Achenes 4-5-ribbed. 



6. Achenes not beaked. 

 1. Involucral bracts in a single row. 

 U)4. Crepis. Pappus white, soft. Flowers yellow or orange. 



2. Bracts in more than one row. 



105. Prenanthes. Involucre calyculate. Achenes short, blunt. Pappus whitish, tawny, or 



brown. Flowers white, cream-color, or pinkish. 



106. Hieracium. Involucre imbricated. Pappus tawny. Flowers yellow or orange. 



Artificial Key to Genera 

 SERIES I. DISK-FLOWERS WITH TUBULAR REGULAR COROLLAS ; LIGTILATB 



FLOWERS IF PRESENT MARGINAL. 



1. Hays or ligulate flowers none; corollas all tubular (or rarely none). 



* Flowers of the head all perfect and alike a. 



a. Pappus composed of bristles ft. 



l>. Pappus double, the outer of very short, the inner of longer bristles . 1. 



>>. Pappus simple, the bristles all of the same sort c. 

 c. Heads few- 



flowered, themselves aggregated into compound or 

 dense clusters ........ 'J. Elei>h<tnt<>i>nx. 



c. Heads separate d. 

 d. Receptacle (when the flowers are pulled off) bristly-hairy. 



Leaves not prickly ......... 80. Ar<-fiiim. 



weaves prickly. 

 Filaments glabrous, united into a tube ..... 85. SiJi/butn. 



Filaments paptDoMfpilOM, separate. 

 Pappus-bristles not plumose ....... 82. </;</////*. 



Pappus-bristles plumose ....... 88. <'ir*in>/i. 



l. Receptacle deeply honeycomb-like ....... 84. 



d. Keeeptaele naked. 



Pftppuft-briatlea plumose. 



CorollM rose-color or porple ; heads racemose or spicate . '.'. 

 Corollas whitish ; heads corymbose ...... S 



Pappus-bristles sometimes roughened but not plumose. 

 Stem twining ; leaves opposite, triangular-haMate . . f>. 



Stem not twining. 



Achenes 5-angled, 5-ribbed ....... 4. 



Achenes 8-10-ribbed or without definite angles or ribs. 

 Annual .......... 77. 



Perennial. 



Flowers yellow. 



Involucral bra. -ts much imbricated in several series . 18. 

 Involucre simple or merely calyculate . . .79. Senecio. 



