APPENDIX A 



539 



of a naked, pitted general receptacle (gr.). \\'ithin are nnmerous ligiilate 

 florets, which are all alike, and have the same number and relation of parts 



as in the Tubulitlorae. But the split 



ligulate corolla shows by its fi\'e teeth 



at the distal end that it is composed of 



five petals. 



The polliiialion-iiiechaiiism is founded 



on protandry. The elongating style 



sweeps out the pollen during the first 



stage of flowering ; the stigma then 



expands and is receptive during the 



second stage. The heads expand in 



sunshine, and intercrossing is possible 



by many different insects. Self-poUina- 



tion is also possible by the recurved 



stigmas coming in contact with pollen 

 adhering to the style. It has, however, 

 been found that in certain cases the 

 fruit of the Dandelion can be matured 

 without an)- pollination at all, even 

 in buds from which the anthers and 

 stigmas have been all cut awaj- before 

 flowering. 



The fniiliiig Jiead is the well-known 

 Dandelion " clock." The individual 

 fruit is a dry inferior achene or nut, 

 attached by a long beak to the para- 

 chute-like pappus. These fruits are 

 easily detached by wind, being exposed 

 on the convex growth of the receptacle, 

 owing to the curiing back of the invo- 

 lucre (Fig. 445). They are thus scat- 

 tered long distances by the wind. The success of the Compositae as a 

 Family depends largely upon the certainty of each floret producing a good 

 fruit, and on the effective dispersal of the fruit by the wind. 



Fig. .h3- 

 rruit ol Dandelion, with pappus ; 



, piurachute. 



