64 Key to the System of 



314. Marginal flowers bearing imperfect fruits. 



Herbs ; leaves broad, indented or incised or pinnatisected ; 

 involucral bracts nearly herbaceous, broadish, in about 

 two rows ; very small bracts between all the flowers ; 

 marginal flowers uniseriate, their corollas forming a yel- 

 lowish or whitish ray ; pappus consisting of two to four 

 rough spinules. Bidens. 1331 



Marginal flowers also bearing perfect fruits. 



Herbs ; leaves mostly basal, often dissected ; involucral 

 bracts nearly herbaceous, narrow, in about two rows ; 

 marginal flowers uniseriate, forming a yellowish ray ; 

 very small bracts between all the flowers ; pappus con- 

 sisting of two rough spinules. Glossogyne. 1332 



315. Involucral bracts almost equal. 



Leaves rather broad ; involucral bracts nearly herbaceous, 

 in about two rows ; marginal flowers uniseriate ; very 

 small bracts between all the flowers. (Transferable to 

 Wedelia.) Figure 87. Eclipta. 1333 



Involucral bracts very unequal. 



Leaves rather broad ; involucral bracts almost herbaceous, 

 in about two rows, the outer narrow-spatular, the inner 

 nearly ovate ; marginal flowers uniseriate ; very small 

 bracts between all the flowers. Siegesbeckia. 1334 



316. Corollas all purplish. (Also those of some Asters) ... 317 

 Corollas all or some yellowish ... ... ... 319 



317. Bracts between the flowers present. 



Rather tall but not woody plants ; leaves scattered, some 

 basal, usually pinnate-lobed ; headlet of flowers large, 

 singly terminal ; involucral bracts in several rows, almost 

 scarious, orbicular and jagged towards the summit; 

 bristlet-like bracts copious between the flowers ; corollas 

 all tubular to near the summit ; pappus-bristlets slightly 

 plumous. (Centaurea partly). iLeuzea. 1335 



Bracts between the flowers absent ... ... ... 318 



318. Flowers within each involucre all of one form. 



Herbs or shrubs ; leaves scattered ; headlets of flowers 

 small, almost paniculated ; involucral bracts in several 

 rows ; corollas all tubular to near the summit ; pappus- 

 bristlets in two rows, the outer minute. Vernonia. 1336 



