COMPOSITE. 107 



3G. Kudbcck'la. Rays yellow, usually long ; dislc darh-purple, or in 

 one species greenish-iieUow. Scales tf the involucre Icuf-like. 

 Receptacle conical. Pappus none, or only a minute crown. 

 Ray-florets neutral. 



37. Ilellan'tUiis. Rays yellow, neutral. Receptacle flattish or 



convex. Chaff persistent, and embracing the i-sided acJienes. 

 Pappus deciduous, of 2 thin scales. Stout coarse herbs. 



38. Actinoni'erls. Rays 2-8, irregular, yellow, neutral. Receptacle 



small, convex. Scales of the involucre few, soon deflexed. 

 Achenos flat, obovatc, spreading when ripe. Pappus of .2 or 3 

 smooth awns, persistent. Tall branching perennials, with 

 mostly decurrent leaves. 



39. Coreop'sls. Rays mostly 8, yellow (sometimes brown-tinted), 



neutral. Receptacle flat. Involucre doable, each of about 8 

 scales, the outer leaf-like and spreading, the inner rather 

 niclnbranaceous and appressed. Achcncs flat, compressed 

 parallel with the scales of the involucre, 2-toothed or some- 

 times naked. Heads corymbed. 



40. Gaillarfl'i.t. Rays yellow (sometimes purplish), numerous, 3- 



cleft. Receptacle convex, the chaff bristly or awl-shaped. 

 Achencs top-shaped, 5-ribbed. Pappus of several long thin 

 scales, awn-tipped. Heads showy, fragrant, terminal, on scape- 

 like stems. — N.W. 



11. Bidens. Rays yellow, few; but 2 species are without rays. Scales 



of the involucre in 2 rows, the outer large and leaf -like. Ray- 

 florets neutral. Aohencs crroitmed with ^ or m.ore sti^ awns 

 which are barbed backward, 



12. Hellop'sis. Rays yellow, 10 or more, pistillate. Scales of the 



involucre in 2 or 3 rows, the outer leaf-like. Receptacle coni- 

 cal ; chaff linear, Achenes smooth, 1-angled. Pappus none. 



13. AcIilHe'a. Rays white (occasionally pinkish), few. Receptacle 



flattish. Pappus none. Achenes margined. Heads small, in 

 flat corymbs. Leaves very flnely dissected. 



11. Polyiu'iila. RayS whitish-yellow, wedge-form, shorter than the 

 involucre, few in number. Scales of the involucre in 2 rows, 

 the outer leaf-like, the inner small, and partly clasping the 

 achenes. Pappus none. Coarse clammy herbs with an un- 

 pleasant odour. 



15. Sil'phinm. Easily known by its stout square stem, and the 

 upper connate leaves forming a sort of cup. Flowers yellow. 

 * Achenes broad and flat. 



