326 Key to the System of 



1464. Leaves strongly decurrent. 



A desert-shrub ; leaves very small, linear, truncate at the 

 summit, wrinkled -rough, shining ; headlets of flowers 

 very small, crowded into corymbs, almost unexpanding, 

 hardly turgid ; iiivolucral bracts yellowish-white ; flowers 

 several within each involucre ; fruits papillular-rough. 



H. decurrens. 



Leaves faintly decurrent. 



A desert-shrub; leaves quite small, cuneate-linear, repressed 

 at the summit, revolute along the margin, smooth or 

 occasionally rough on the upper side, beset with short 

 vestiture on the lower side ; headlets of flowers very 

 small, crowded into compound corymbs, quite unexpand- 

 ing, turgid ; involucral bracts pale-yellowish or sometimes 

 reddish, almost glabrous, shining ; flowers rather few 

 within each involucre, two or three of the outer without 



stamens and pappus ; fruits papillular-rough. 



H. 



retusum. 



WAITZIA. 



1465. Terminal attenuation of the fruit very thin, longer 



than the seed-bearing portion. 



Erect, somewhat beset with short hairlets ; leaves never 

 quite short, the uppermost reaching the inflorescence ; 

 headlets of flowers almost corymbously arranged ; in- 

 volucral bracts broadish, very acute, shining, yellow or 

 white or the lower red, the upper spreading or even 

 repressed ; the laminas of all similar in form and mostly 

 in size, minutely ciliolate ; fruits somewhat papillular- 

 rough. W. corymbosa. 



LEPTORRHYNCHOS. 



1466. Involucral bracts mostly blunt ... ... ... 1467 



Involucral bracts mostly pointed ......... 1468 



1467. Involucral bracts tender-membranous, dull- and pale- 



colored. 



Annual, rather robust, somewhat beset with cottony vesti- 

 ture ; leaves from lanceolar- to broad-linear, recurved 

 along the margin ; headlets of flowers comparatively 

 large, from semiovate to finally hemispherical ; involucral 

 bracts almost colorless and nearly without lustre, slightly 

 wrinkled, the outer somewhat elliptical ; pappus-bristlets 

 rather numerous ; fruits terminated by a thin attenuation. 



L. Waitzia. 



