COMPOSITAE. 



351 



short chaffy teeth or 

 awns. 



Rays pistillate and fer- 

 tile. 



Rays neutral. 

 Receptacle not chaffy. 

 Tegules in one row. 



Akenes obpyramidal; re- 

 ceptacle naked. 

 Akenes linear, more or less 

 4-angled; receptacle 

 beset with bristly 

 points. 



Tegules distinct. 

 Tegules united into a 



cup. 

 Tegules in more than one 



row. 



Tegules in many rows. 

 Tegules in two or three 



rows. 

 Receptacle bristly; 



pappus present. 

 Receptacle naked; pap- 

 pus present or 

 none. 



Pappus of 4 or 5 trun- 

 cate scales, erose 

 or lacerate at the 

 tip or nearly en- 

 tire. 



Pappus none. 



Pappus of capillary bristles. 

 Ray-flowers not yellow. 



Tegules in 1 or 2 series, nar- 

 row; ray-flowers usually 

 narrow and numerous. 

 Tegules in 2-5 series; ray- 

 flowers broader, less 

 numerous. 



Involucre narrow, with 

 rigid bracts; ray-flowers 

 white, 4 or 5. 

 Involucre turbinate or 

 hemispheric; ray- 

 flowers more than 5. 

 Stems scape-like. 

 Stems leafy. 



Tegules dry and 

 chartaceous, 

 closely appress- 

 ed. 



Tegules more or less 

 herbaceous and 

 spreading. 

 Ray-flowers yellow. 



Pappus double, the outer row 

 very short. 



519. WYETHIA, 376. 



520. HELIANTHUS, 377. 



526. HELENIUM, 379. 



522. BAERIA, 377. 



523. ERIOPHYLLXJM, 378. 



501. GRINDELIA, 362. 

 525. GAILLARDIA, 378. 



524. 

 521. 



HULSEA, 378. 

 JAUMEA, 377. 



506. ERIGERON, 366. 



507. SERICOCARPUS, 369. 



508. OREOSTEMMA, 370. 



509. BUCEPHALUS, 370. 



510. ASTER, 371. 

 502. CHRYSOPSIS, 363. 



