776 coMPOSiTAE (composite family) 



* * * ♦ Pappus composed entlraly of capillary bristles, not plamose. 

 4- Achenes strongly marlcate or splnuloso above. 



97. Chondrilla. Stem branching, leafy. Involucre few-flowered, calyeulate. Aobenes terete, 



several-i-ibbed. 



98. Taraxacum. Seapose. Involucre calyeulate, many-flowered. Achenes fusiform, 4-5-ribbed. 



+- -I- Achenes not muricate above. 

 f+ Achenes flat or flattlsh. Pappus white, flue and soft.< Involucre Imbricated. Leafy-stemmed, 

 with panicied 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. Seapose. Involucre loosely imbricated. Achenes 10-ribbed. 



103. Pyrrbopappus. Seapose or branched. Aehenes 4-5-ribbed. 



b. 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 calyeulate. 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 ; ligulatb 



FLOWERS IF PRESENT MARGINAL, 



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



* Flowers of the head all perfect and alike a. 

 a. Pappus composed of bristles 6. 



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

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

 <i. Heads few-flowered, themselves aggregated Into compound or 



dense clusters 2. Elephwntojms. 



o. Heads separate d. ^ -r 



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



Leaves not prickly 80. Arctium. 



i^eaves prickly. 



Filaments glabrous, united Into a tube 85. SUyhuin. 



Filaments papillose-pilose, separate. 



Pappus-bristles not plumose 82. Carduvs 



Pappus-bristles plumose 83. Cirsium' 



a. Receptacle deeply honeycomb-like 84. Ono-pordwm, 



d. Receptacle naked. 



Pappus-bristles plumose. 

 Corollas rose-color or purple ; heads racemose or spioate . 9. Liatris 



Corollas whitish ; heads corymbose 8. Kuhnia. 



Pappus-bristles sometimes roughened but not plumose. 

 Stem twining ; leaves opposite, triangular-hastate . , g. Mikania 



Stem not twining. 



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



Achenes 8-10-rlbbed or without deflnite angles or ribs 



vZTL. • • "• '^-<'*«^- 



Flowers yellow, 

 Involucral brncts much Imbricnted tn several series . IB. Biaeloioia 

 Involucre simple or merely calyeulate , , .79, Seneeio. ' 



