COMPOSITAE. 



349 



Heads in a corymb ; 

 pappus a short 

 crown. 532. 



Heads in a raceme 

 or panicle; pap- 

 pus none. 533. 

 Staminate and pistillate flowers in 

 different heads. 

 Pappus capillary; fertile involu- 

 cre not bur-like. 

 Leaves prickly; heads large. 

 Leaves not prickly; heads 

 small. 

 Pappus of staminate flow- 

 ers either club-shaped or 

 barbed at the apex. 54 L 

 Pappus of all the flowers 

 alike and neither club- 

 shaped nor barbed. 542. 

 Pappus none; fertile involucre 

 bur-like. 

 Bracts of staminate heads 

 separate; bur large, with 

 many tegules. 497. 

 Bracts of staminate heads uni- 

 ted; bur small, with 1-4 

 tegules. 498. 

 Flowers of the heads all perfect and 

 alike. 

 Pappus of separate capillary bristles. 

 Flowers whitish, cream-colored 

 or purplish. 

 Leaves in whorls of 3 to 6. 

 Leaves alternate or opposite. 



Heads about 10-flowered. 535. 



Heads about 40-flowered. 500. 



Flowers yellow or brownish. 



Tegules in 3 or 4 rows. 



Tegules in 1 row or nearly so. 



Involucre hemispheric to 



rotate. 

 Involucre campanulate or 

 cylindric. 

 Heads many-flowered. 539. 

 Heads 4-7-flowered. 536. 

 Pappus not of separate capillary 

 bristles. 

 Pappus of numerous bristles uni- 

 ted into a ring at the base. 

 Filaments monadelphous be- 

 low. 547. 

 Filaments distinct. 



Leaves never prickly. 550. 



Leaves more or less prick- 

 ly. 548. 

 Pappus not of bristles united in a 

 ring. 



Tanacetum/SSL 

 Artemisia, 381. 



548. CiRSiUM, 394. 



Antennaria, 390. 

 Anaphalis, 392. 



Xanthium, 361. 

 Gaertneria, 361. 



499. Eupatorium. 361. 



LuiNA, 383. 



COLEOSANTHUS, 362. 



503. HOOREBEKIA, 363. 



506. Erigeron, 366. 



Senecio, 386. 

 Rainiera, 383. 



SiLYHUM, 394. 



Saussurea, 396. 

 Cirsium, 394. 



