200 



SPECIAL EXERCISES ON TYPICAL FLOWERS 



For study of pistil use the oldest blossoms, and for stamens 

 the buds which are about ready to burst. 



Split open the long tube and see if you can find any trace 

 of nectar in its depths. Its object? Draw a flower, top 

 view, showing the arrangement and number of the parts; 

 also a view of the split corolla. Draw one stamen and a 



Top 



PttHL.J 



FIG. 88. Evening primrose. 



view of the ovary. Cut open a mature ovary crosswise 

 and make out the attachment of the ovule. Can you dis- 

 cover any lines or seams (sutures) where the fruit will split 

 when it becomes ripe ? Draw pollen highly magnified. 



Method (Field). Take your station near an evening prim- 

 rose plant just about sunset and listen for the explosions 

 which accompany the opening of the flowers. What insects 

 visit these flowers ? See if you can discover how they extract 

 the nectar. 



Note. For comparison study willow-herb (epilobium). Both 

 evening primrose and willow-herb are good for autumn as well as 

 spring classes, since they usually blossom until frost. 



