72 HANDBOOK OF NATURE STUDY 



is called a pinnate leaf. Good examples of pinnate leaves 

 are the leaves of roses, peas, and vetches. 



The flowers of the Box Elder appear early in spring, 

 with the leaves or before them. The sterile and the fertile 

 flowers are on different trees. The sterile ones appear in 

 drooping bundles; they have no corolla, the stamens are 

 attached to a long thread and surrounded by a small green 

 calyx. After the pollen is shed, the sterile flowers wither 

 and drop off. 



The fertile flowers appear in drooping clusters ; they also 

 are destitute of a corolla. Each flower has two styles which 

 look like a small, bent horn. The fertile flowers develop 

 into seeds, and when the seed is full grown, each has de- 

 veloped a wing. The seeds are not ripe until late in the 

 fall. They drop off very slowly, and some are still on the 

 tree the next spring. 



The Box Elder, although its native home is the borders 

 of streams and lakes, will thrive in almost any kind of soil, 

 in this part of the country, although, like nearly all trees, it 

 prefers moist and loose soil. It grows very fast. In one 

 season young trees commonly produce shoots three feet 

 long. Its foliage is very dense, and, if the young trees are 

 not planted too far apart, they soon kill weeds and grasses 

 by their dense shade. The fact that the tree remains rather 

 small, makes it more desirable near buildings, because, in 

 case of a storm, it does not endanger them by falling limbs. 

 These qualities make the Box Elder one of the most desirable 

 shade trees in our Northern and Northwestern States. 



The wood of the Box Elder has no special value. Find 

 out for yourself about its color and hardness. 



NOTE. The insects principally injurious to this tree are the Box 

 Elder Bug, the Box Elder Leaf Roller, and leaf-lice. About these 



Observations. What are some of the plants most easily raised in houses? 



