COMPOSITAE (COMPOSITE FAMILY) 



779 



Eleoeptacle flat or nearly so. 



Achenes cylindrical, 2-aw'ne(i 56. Thele»p«rm,a. 



Achenes flattened parallel to the chaff. 



Pappus-awns barbed 5G. Bid ens. 



Pappus-awns not barbed 54. Coreopsis. 



Beceptacle convex to columnar. 



Involucral bracts with thin scarions margins . . . .68. Anthemis. 



Involucral bracts distinctly herbaceous. 

 Pappus of 2 awns. 



Pappus-awns very deciduous 51. Heluinthus. 



Pappus-awns persistent 52. Actinomeris. 



Pappus none or a crown of short teeth. 



Kays rose-color (rarely yellow), pistillate . . , ,47. Brauneria. 

 Kays yellow to brownish-red or orange, neutral. 



Achenes 4-sided, marginless 46. Riulheckia. 



Achenes flattened and margined 48. Lepachys. 



■u Rays pistillate and fertile r. 



l>. Disk-flowers also fertile, their achenes maturing s. 

 s. Leaves alternate. 



Pappus of 1-8 awns or teeth 53. Verhesina. 



Pappus none. 

 Heads less than 1 cm. broad ; achenes obcompressed . . 67. Ac/iillea. 

 Heads more than 1 cm. broad ; achenes not compressed . 68. Anthemis. 

 8. Leaves opposite. 



Maritime shrub 50. BorricJiia. 



Herbs. 



Annual, with white rays 44. Eclipta. 



Perennial, with yellow' rays. 



Outer involucre of 4 connate bracts 45. Tetragonotheca. 



Outer involucral bracts not connate. 



Weak creeping herb 49. Spilanthes. 



Stout erect herbs. 



Achenes laterally flattened 53. Verhesina. 



Achenes thickish 43. Heliopsis. 



r. Disk-flowers not maturing achenes ; disk chaff'y. 

 Achenes thickish, not strongly flattened. 



Inner bracts of the involucre not armed 83. Polymnia. 



Inner bracts of the involucre glochidiate, closely investing the 



achenes M. Acanthospermum. 



Achenes flattened dorsally. i.e. parallel with the chaff. 

 Rays 5, obcordate, scarcely exceeding the disk, whitish . . 33. Parihenium. 

 Kays yellow, much longer than the disk, 

 Achenes wing-margined, in several rows . . . .35. Silphium. 

 Achene wingless, in a single row. 



Kays 5 ; leaves serrate 37. Chrysogonum. 



Ka3's usually more numerous ; leaves dentate or lyrately 



lobed 86. BerlandAera. 



Series II. All the flowers op the head with strap-shaped corolla i. 



I. Pajjpus none. 



Leaves basal 90. Arnoseris. 



Leafy-stemmed. 



Involucre calyculate 88. Laj)sana. 



Involucre uot calyculate 89. Serinia. 



t. Pappus wholly or in part of scales. 



Flowers blue, rose-colored, or rarely white 91. Cichoruim. 



Flowers yellow 92. Krigia. 



t. Pappus bristle-formed, capfllary u. 

 u. Bristles plumose. 

 Leaves basal. 



Inner achenes long-beaked , . . 93. ITypcchaeria. 



Inner achenes not beaked 94. Leoniodon. 



Leafv-stemmed. 



Hispid-pubescent 95. Picris. 



Glabrous 96. Tragopogon. 



u. Bristles simple, at most scabroiis r. 



V. Achenes strongly muricate or spinulose above. 



Leafy-stemmed 97. Chondrilla. 



Scapose 98. Taraxacum. 



V. Achenes not muricate above tc. 

 w. Achenes flat or flattish. 



Achenes beakless ; flowers 50 or more in each head, yellow . 99. Sonchus. 

 Achenes mostlv beaked ; heads C-;30-flowered ; flowers yellow, 



blue, or purple 100. Lactuca. 



to. Achenes columnar, often slender. 



Flo%vers cream-color, white, rose-color, or purple. 



Pappus white ; heads erect 101, Lygodesmia. 



Pappus cream-color or tawny ; heads nouding .... 105. Prenanthe^. 



