434 SYNGENESIA. 



some others, occasionally have their whole 

 disk changed to ligulate white florets, desti-- 

 tute of stamens, and consequently abortive. 

 Such are actually called double flowers in this 

 Class, and very properly. Many exotic spe- 

 cies so circumstanced are met with in gardens. 

 A few very strange anomalies occur in this 

 section, as already mentioned, p. :)06, one 

 Sigesbeckia having but 3 stamens, instead of 

 5, the otherwise universal number in the 

 Class ; and Tiissilago hi/brida, t. 430, as well 

 as paradoxa of Retzius, having distinct an- 

 thers. Nature therefore, even in this most 

 natural Class, is not quite without exceptions. 



5. Tolygamin frustranea. Florets of th^ 

 disk, as in the preceding, perfect or united ; 

 those of the margin neuter, or destitute of 

 pistils as well as of stamens ; only some 

 few genera having the rudiments of pistils 

 in their radiant florets. 



This Order is, still more evidently than 

 the last, analogous to double flowers of 

 other Classes. Accordingly, Coreopsis is 

 the very same genus as Bidens, only fur- 

 nished with unproductive radiant florets. 

 C. bidens of Linnaeus is the same species 



