348 



COMPOSITAE. 



Flowers not yellow. 



Akenes long-beaked. 485. 



Akenes beakless, with a truncate 



summit. 486. 



Flowers yellow. 



Receptacle chaffy. 487. 



Receptacle not chaffy. 



Leafy-stemmed biennials or 



perennials. 488. 



Acaulescent annuals. 489. 



Pappus of capillary bristles, never 



plumose. 

 Heads solitary; leaves all basal. 



Akenes muricate or spinulose at 



the apex. 490. 



Akenes smooth at the apex. 491. 



Heads several; leaves not all basal. 

 Akenes flattened. 



Akenes beaked, if short- 

 beaked flowers not yellow. 495. 

 Akenes beakless; flowers yel- 

 low. 496. 

 Akenes terete, cylindric or pris- 

 matic. 



Flowers purplish. 

 Flowers yellow or white. 

 Pappus copious, white 



and soft. 

 Pappus a single row of 



rough tawny bristles. 



Corollas tubular in all the flowers of the head or 

 strap-shaped in only the marginal ones; 

 plants without milky juice. 

 Ray-flowers none; corollas all tubular. 



Flowers of the head not all alike, some 



heads having imperfect flowers. 

 Perfect and imperfect flowers in the 



same head. 



Marginal flowers neutral and 

 sterile, often larger than the 

 central ones, resembling ray 

 flowers. 



Marginal flowers perfect or pistil- 

 late and fertile, not resem- 

 bling ray flowers. 

 Pappus of capillary bristles. 



Tegules in one row. 534. 



Tegules in several rows. 543. 

 Pappus a short crown or none. 

 Leaves entire or nearly so, 



ovate. 



Leaves incised, lobed or 

 dissected, or if en- 

 tire lanceolate. 

 Pistillate flowers apet- 



alous. 



Pistillate flowers with 

 tubular corollas. 



TRAGOPOGON, 352. 

 CICHORIUM, 353. 

 HYPOCHAERIS, 353. 



SCORZONELLA, 353. 

 MlCROSERIS, 354. 



TARAXACUM, 355. 

 AGOSERIS, 355. 



LACTUCA, 359. 

 SONCHUS, 360. 



494. NABALUS, 359. 



493. 

 492. 



CREPIS, 358. 

 HIERACIUM, 356. 



546. CENTAUREA, 393. 



PETASITES, 382. 

 GNAPHALIUM, 392. 



545. ADENOCAULON, 393. 



531. COTULA, 381. 



