644 CONTEIBUTIONS FEOM THE NATIONAL HEEBAEIUM. 



Rays present. 

 Involucral bracta Bpatulate or linear-oblanceolate; raya 

 deeply cleft, purple; heads turbinate. 



100. Othake (p. 722). 

 Involucral bracts obovate or broadly oblong; rays not deeply 

 cleft, not purple; heads campanulate. 

 Rays inconspicuous, scarcely exceeding the disk; heads 

 small; plants glabrous. -.101. Hymenothrix (p. 722). 

 Rays large, white; heads large; plants tomentose. 

 Pappus of numerous prominent palese. 



99. Hymenopappus (p. 720). 

 Pappus an obscure crowii . . .102. Leucampyx (p. 723). 

 Bracts neither colored nor scarious. 



Flowers pink 103. Chaenactis (p. 723). 



Flowers never pink, mostly yellow. 

 Achenes 4-angled. 

 Leaves alternate. 

 Leaves entire; pappus of 10 palese. 



107. Platyschkuhria (p. 725). 

 Leaves dissected; pappus wanting or of 12 or more scales. 



108. Villanova (p. 725). 

 Leaves, at least the lower, opposite. 

 Foliage not impressed-punctate; receptacle conic; leavea 



entire 104. Baeria (p. 723). 



Foliage impressed-punctate; receptacle flat or convex; 

 leaves dissected. 

 Annuals; leaf segments filiform or nearly so. 



106. Achyropappus (p. 724). 

 Perennials; leaf segments oblong to linear. 



Leaf blades impressed-punctate; involucral bracts 



carinate. 105. Picradeniopsis (p. 724). 



Leaf blades not impressed-punctate; bracts not cari- 

 nate 105a. Bahia (p. 724). 



Achenes 5 to 10-ribbed. 



Bracts of the involucre spreading or reflexed. 



Leaves decurrent; tubes of disk corollas very short or reduced 



to a ring 109. Helenium (p. 726). 



Leaves not decurrent; tube of the disk corollas long. 



110. Dugaldea (p. 726). 

 Bracts of the involucre erect, never spreading nor reflexed. 

 Pappus wanting; involucres few-flowered. 



111. Flaveria (p. 726). 

 Pappus present; involucres many-flowered. 

 Bracts of the involucre unequal, the outer united at the 

 base. 

 Leaves opposite; plant glabrous. 



112. Sartwellia (p. 727). 



Leaves alternate or basal; plants more or less pubescent. 



Stems monocephalous; plants woody throughout. 



113. Macdougaua (p. 727). 

 Stems branched and bearing numerous heads; 

 plants sparingly if at all woolly. 



114. Hymenoxys (p. 727). 



