312 Key to the System of 



1413. Involucral bracts few, nearly orbicular. 



Chiefly a coast-plant, creeping, dwarf, nearly glabrous; -leaves 

 somewhat succulent, long-stalked, their segments rather 

 broad, incised ; receptacle conical ; flower-stalks with 

 leaf-stalks from nodes of the creeping stems, much 

 elongated \ marginal flowers in several rows, their fruits 

 bluntly margined. C. reptans. 



Involucral bracts several, nearly oval. 



An alpine dwarf plant, much beset with, soft hairlets ; 

 leaf-segments rather broadish, often somewhat indented ; 

 headlets of flowers on short and robust stalks ; receptacle 

 conical ; marginal flowers in several rows, their fruits 

 unprovided with stalklets, thickly margined. 



C. Filicula. 



CENTIFHDA. 



1414. Mostly prostrate. 



Perennial odorous herb, rather weak; leaves mostly elliptic- 

 cuneate, towards the base narrow and entire ; headlets of 

 flowers somewhat stalked, almost hemispherical ; invo- 

 lucral bracts hardly membranous at the margin ; flowers 

 emersed ; -outer flowers in several rows, their corolla 

 minute; fruits upwards ellipsoid, streaked to the summit. 

 "Sneeze- weed." C. orbicularis. 



Mostly erect ... ... ... 1415 



1415. Headlets of flowers almost hemispherical. 



Perennial odorous herb, rather robust ; leaves also towards 

 the dilated base denticulated, often somewhat crisped ; 

 headlets of flowers relatively large, sessile ; involucral 

 bracts membranous at the margin ; flowers emersed ; 

 outer flowers in numerous rows, their corolla minute ; 

 fruits upwards cylindrical and there streakless. Figure 88. 



C. Cunningham!. 



Headlets of flowers almost semiovate. 



Perennial desert-herb ; leaves denticulated also towards the 

 dilated base ; headlets of flowers relatively large, sessile ; 

 involucral bracts membranous at the margin ; flowers 

 enclosed ; outer flowers in few rows ; corolla of all flowers 

 turgid towards the base ; fruits upwards cylindrical and 

 there streaked. C. thespidioides. 



