182 



ZESSOJfS WITH PLANTS 



whereas in the dandelion the outer row is reflexed. 

 The pupil should now explore the involucres of 

 compositous flowers, noting espe- 

 cially the spiny scales of the this- 

 tles, the hooked scales 

 of the burdock and the 

 great leafy scales of the 

 common sunflower. In 

 other words, there is as 



Pig. 176. 



Bell-shaped and proterandrous 

 flowers of common bell-wort. 



FlO. 177. 



Salver-shaped corolla and con- 

 volute eestiyation of phlox. 



great variation in the involucre as in other mem- 

 bers of plants. 



Suggestions. — The pupil should designate the parts in the floret 

 of the wild aster (ffig. 175); and the same exercise should be 



