Teachers' Corner 



How to Study a Composite Flower 



Many plants have their flowers set close together to make a mass of color, 

 like the geraniums or the clovers. But there are other plants where the 

 flowers of one flower-head act like the members of a family, those at the center 

 doing a certain kind of work for the production of seed, and those around the 

 edges doing another kind of work. The sunflower, goldenrod, asters, daisies, 

 cone-flower, and many other common flowers have their blossoms arranged in 

 this way. Before any of the wild-flower members of this family are studied, the 

 lesson on the garden sunflower should be given. 



1 . Note that what you call the flower consists of many flowers set together 

 like a beautiful mosaic. Those at the center are called disk-flowers; those 

 around the edges banner or ray-flowers. 



2 . Note that the flowers around the edges have differently shaped corollas 

 than those at the center. How do they differ? Why should these be called 

 the banner flowers? Why should they be called the rayflowers? How many 

 banner flowers are there in the flower family you are studying? How are the 

 banners arranged to make the flower-head more attractive? Cut off or pull 

 out all the banner-flowers and see how the flower-head looks. What do the 

 banner-flowers hold out their banners for? Is it to attract us or the insects? 

 Has the banner-flower any stigma or stamens? 



3. Study the flowers at the center. Are they open, or are they unfolded, 

 buds? Can you make a sketch of how they are arranged? Are any of the 

 florets open? What is the shape and the color of the corolla? Can you see the 

 stamen-tubes pushing out from some? What color are the stamen-tubes? 

 Can you see the two-parted stigmas in others? What color is the pollen. Do 

 the florets at the center or at the outside of the disk open first? When they 

 first open, do you see the stamen- tube or the stigma? 



4. The flower-heads are protected before they open with overlapping bracts. 

 As the flower-head opens, these bracts are pushed back beneath it. Describe 

 the shape of these bracts. Are they set in regular, overlapping rows? Are 

 they rough or smooth? Do they end bluntly, with a short point, with a long 

 point, with a spine, or a hook? How do the bracts act when the flower family 

 goes to sleep? Do they remain after the seeds are ripened? 



5. Take a flower-head apart, and examine the florets. Can you see what 

 part of the floret will be the seed? Is there a fringe of pappus above it? If so, 

 what will this be on the seed? 



6. Study the ripe seeds. How are they scattered? Do they have balloons? 

 Is the balloon close to the seed? Is it fastened to all parts of it? 



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