776 COM PCS IT A E (composite family) 



* * * * Pappus composed entircjly of capillary bristles, not plamose. 

 ■»- Achenes strongly muricate or spinulose above. 

 97. Chondrilla. Stem branching, leafy. In\olucre few-flowered, calyculate, Achenes terete, 



-cNcral-ribbed. 

 96. Taraxacum. Scapose. Involucre calyculate, many-flowered. Achenes fusiform, 4-6-ribbed. 



4- -•- Achenes not muricate above. 



*+ 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. • 



++ ++ Achenes columnar, often slender. 



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



101. Lygodesmia. Achenes long, slightly tapering above. Pappus white. Stems 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 lO-ribbed. 



103. Pyrrhopappus. Scapose or branched. Achenes 4— 5-ribbed. 



6. Achenes not beaked. 

 1. Involucral bracts in a single row. 



104. 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. 

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



Artificial Key to Genera 

 Series I. Disk-flowers with tubular regular corollas ; ligulate 



FLOWERS IF PRESENT MARGINAL. 



§ 1. Bays or ligulate floioers none; corollas all tubular (or rarely none), 



* Flowers of the head all perfect and alike a. 



a. Pappus composed of bristles b. 



b. Pappus double, the outer of very short, the inner of longer bristles . 1. Vernonia, 

 b. Pappus simjile, the bristles all of the same .sort c. 

 c. Heads few-flowered, themselves aggregated into compound or 



dense clusters 2. Elephantopus. 



c. Heads sei)arate d. 

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



Leaves not j)rickly 80. Arctium. 



Leaves prickly. 



Filaments glabrous, united into a tube 85. Silybum. 



Filaments papiliose-r>ilo8e, separate. 



Pap[nis-bristies not plumose 82. Carduus. 



Pappus-bristles plumose 83. Cimium. 



d. Receptacle ileei)ly honeycomb-like 84. Onopordum. 



d. Keceptacie iiakoil. 



Papjius-bristles plumose. 

 (Jorollas rose-color or purple ; heads racemose or spicate . 9. Liatris. 



Corollas whitish ; heads corymbose 8. Kuhnia. 



Pappus-bristles sometimes roughened but not plumose. 

 Stem twining; leaves opi)08ite, triangular-hastate . . 5. Mikania. 



Stem not twining. 



Achenes Wangled, fi-ribbed 4. Eupatoriwm. 



Achenes S-lo-ribln-d or without definite angles or ribs. 



Annual 77. ErechtiteH. 



Perennial. 



Flowers yi'llow. 

 Involucral t>racts much iinbiicatcd in several series . 18. Bi<jeln\iiia. 

 Involucre simple or merely calyculate . . .79. Senficio 



