146 



FIEST STUDIES IN PLANT LIFE 



Fit 101 



Winged 



seed of 



pine. 



climbs on trees or high poles, and so we are not sur- 

 prised to find that its seeds are winged. One of the 

 simplest of winged seeds is that of the pine. If you 

 break open the hard scales of a pine cone,* 

 you will see that each seed has a wing. 



8. Notice carefully that in many pines 

 the wing is not evenly balanced. Can 

 you guess the purpose of this? The 

 longer the seed takes to reach the ground, 

 the more chance the wind has of blowing 

 it away. Now, if two winged seeds fall 

 from the same point at the same moment, one of 

 which is well-balanced and the other not, which seed 

 wiU take the longer to reach the ground ? 

 Some trees, however, have winged seed 

 with the wings almost evenly balanced. 

 You will see this in the elm, and in 

 the plane tree that is called the 

 sycamore. But the slightest uneven- 

 ness in the balance serves the purpose. 



9. Even without wings a cluster of 

 seed-cases blown ofif a high tree in a 

 storm can travel some distance. Look at the ground 

 near a tall gum tree after a storm, and you may see 

 how gum tree seed-cases are sometimes scattered. 

 The seeds of gum trees, however, often escape fi-om 

 the seed-cases while these are still on the tree. The 

 seeds are, as a rule, small and light, and when they 

 escape from seed-cases on a high branch, they m&y be 

 carried a good way by the wind. 



Winged seed 

 of elm. 



* A hatchet may be needed, if the pine cone be young. Cones often hang 

 for years before the seeds fall out. Alternate sun and rain cause the scales 

 to open, and in this way the seeds become at last free. 



