338 Key to the System of 



1506. Headlets in a contracted panicle. 



Mostly rough from short rigid hairlets ; leaves from elliptic- 

 to linear-lanceolar, indented or lobed, the stem-leaves 

 clasping with their dilated base ; fruits beset with very 

 minute hairlets, circularly margined at the summit. 



E. arguta. 



Headlets in an ample panicle. 



Tall, nearly glabrous ; leaves almost membranous, from 

 linear- to elliptic-lanceolar, often much elongated and 

 rather regularly denticulated ; fruits beset with very 

 minute hairlets, circularly margined at the summit. 



E. prenauthoides. 



SBNECZO. 



1507. Corollas of the marginal flowers flatly much expanded 1508 



Corollas of all flowers tubular to near the summit ... 1517 



1508. Annual ... 1509 



Perennial ..> ... ... ... 1510 



1509. Headlets of flowers always singly terminal. 



Desert-plant, quite glabrous, never tall ; leaves greyish- 

 green, from narrow- to lanceolar-linear, usually entire, 

 the upper sessile ; headlet of flowers rather large, its 

 stalk dilated at the summit ; involucre ample, without 

 any accessory basal bracts ; marginal corollas broadly 

 ligular-expanding ; fruits streaked." S. Gregorii. 



Headlets of flowers generally few together. 



Desert-plant, rather robust but never tall, almost glabrous ; 

 leaves mostly somewhat pinnatifid ; lobes often indented ; 

 headlets of flowers comparatively large, their stalks dilated 

 at the summit ; involucre ample, with hardly any accessory 

 basal bracts ; marginal corollas broadly ligular-expanding ; 

 fruits beset with very short hairlets. S. platylepis. 



1510. Headlets of flowers solitary or few together. 



Alpine plant, always dwarf, nearly glabrous, often branch- 

 less ; basal leaves pinnatifid or regularly short-lobed ; 

 stem-leaves suddenly or gradually much reduced in size 

 and indented only ; marginal corollas conspicuously 

 ligulate ; involucre supported by very small accessory 

 bracts ; fruits slender, glabrous. S. pectiuatus. 



Headlets of flowers several or numerous ... ... 1511 



