COMPOSITAE 



621 



Disk-flowers fertile. 



Ray-flowers persistent upon the achenes. 

 Ray-flowers deciduous, or none. 



Pappus a cup, or crown, or of a few teeth, awns or bristles. 

 Achenes, at leat those of the disk-flowers, not com- 

 pressed (except in Ratibida and Verbesina). 

 Scales of the receptacle small, awn-like or bristle- 

 like; rays white, short. 

 Scales of the receptacle broad, larger. 

 Receptacle conic or columnar. 

 Achenes 4-ang!ed. 

 Achenes compressed, winged. 

 Receptacle flat or convex. 



Achenes not much flattened or winged or 



margined. 

 Achenes of disk flowers flattened and 



margined or winged. 

 Achenes very flat. 



Pappus of 2 short awns or teeth, or 



a mere border, or none. 

 Pappus of 2-6 awns or teeth, barbed 

 and hispid. 

 Pappus of numerous scales; leaves opposite, toothed; rays 



29. Heliopsis. 



small. 



27. Polymnia L 



Rays 12-25 mm. long, yellow; achenes striate. 

 Rays minute, whitish, or none; achenes 3-ribbed. 



30. Eclipta. 



31. rudbeckia. 



32. Ratibida. 



33. Helianthus. 



34. Verbesina. 



35. Coreopsis. 



36. BlDENS. 



37. Galinsoga. 



1. P. Uvedalia. 



2. P. canadensis. 



1. P. Uvedalia L. In rich woods: N. Y. to Ind. and Mich, to 



Fla., Mo. and Tex. 



N. J. Known only from an old record at Weehawken, not since 



collected. 

 Pa. Northampton, Berks, Montgomery, Delaware and Chester 



counties. 



A rare and local species, apparently increasing westward. 



2. P. canadensis L. In damp rich shaded places: Ont. to Minn., 



Ga., Mo. and Ark. 



Apparently confined, in our area, to Middlesex and New Haven 

 counties, Conn., and Chester and Delaware counties, Pa. Rare. 



28. Silphium L. 

 S. perfoliatum L. In moist soil: southern Ont. to S. Dak., 

 south to Ga., Neb. and La. 



Known in our area only as a rarely naturalized plant from the 

 west, especially near New York. 



