772 



Handbook of Nature-Study 



3. Find a pollen-bearing catkin. Describe the stamens. 

 Can you see anything but the anthers ? On what are they set ? 

 What color are they? What color do they give to the tree 

 when they are in blossom? What happens to the catkins 

 after their pollen is shed? 



4. Find a seed-bearing catkin. How long is it? Do you 

 see why this tree is called the necklace poplar? Describe 

 the pistils which make the beads on the necklace. 



5. When do the seeds ripen? If you have been near the tree, how do 

 you know when they are ripe ? How long is the catkin with the ripened 



Seed-pod of 



poplar, shut 



and open. 



Cottonwoods. 

 Courtesy of U. S. Forest Service. 



seeds? How many balls on the necklace now? What is the color? How 

 many seeds come out of each little pod ? How are the seeds floated on the 

 air? Why do we call this tree "cottonwood?" 



6. How large is the largest cottonwood that you know? Sketch it to 

 show the shape of the tree. Are the main branches large? Do they droop 

 at the tips ? 



7. ^ How does the foliage of the cottonwood look? Does it twinkle with 

 the wind ? Examine the leaves upon a branch and see why they twinkle. 

 Are the petioles round or flat ? Are they flattened sidewise or up and 

 down ? Are they stiff or slender? Describe the leaves, giving their shape, 



