226 PRACTICAL LESSONS IN SCIENCE. 



the forms of insects and birds. They are noted for the beautiful 

 color of their flowers and the varied forms of their foliage. They 

 are especially interesting for the many curious devices for cross 

 fertilization by insects and birds. They are very popular as or- 

 namental plants, and are represented in the United States by the 

 lady's slipper and a few other less showy flowers. The vanilla 

 plant is an orchid, and other members of the family are useful, 

 but in general they are of little economic value. 



Another interesting member of this group is the Banana 

 Family. The genus Musa of this family contains the plaintain 

 and the banana of tropical regions. No other genus furnishes 

 food for as many people as does the genus musa. It is estimated 

 that about 25 tons of bananas can be grown upon an acre of 

 ground, furnishing more food per acre than any other plant. 



There are many other interesting plants in this subclass, but 

 the ones mentioned are the most prominent, and will give a good 

 and comprehensive idea of the whole. This monocotyledon group 

 of plants is distinctively the foo d group of the vegetable kingdom. 



