[Chap. LI SOME FAMILIES OF FLOWERING PLANTS 



701 



developed seeds. The family is composed of 6 genera and some 60 

 species. 



The banana is a plant of the tropics and warmer subtropics and 

 takes the place of bread and potatoes in the diet. It is also a source of 

 medicine, of a fermented drink, and of fiber, such as the manila hemp 

 of commerce (Fig. 338). The \'ield of bananas is surprisingl\- large, 



Fig. 338. One of the cultivated varieties of banana. 



often as much as 100 tons to the acre as compared with 2 tons of 

 potatoes. A single bunch of ripe bananas may contain over 200 fruits 

 and sometimes weighs 175 to 200 pounds. Bananas often grow in green- 

 houses in northern latitudes, but the fruits of these plants are not as 

 large or as palatable as those of plants in the tropics. 



The orchid family (Orchidaceae). The orchids constitute the most 

 highly specialized family of the monocots. They are perennial herbs 

 largely terrestrial in temperate regions, but predominantly epiphytic, 

 with aerial roots, in the tropics; some are saprophytic, or parasitic on 

 the roots of other plants. They may be erect or occasionally trailing, 

 and in most cases have fleshy roots, rootstocks, corms, or bulbs. In 

 saprophytic and parasitic species the leaves are mere scales; in all 

 others the leaves are conspicuous, green, and usually alternate. 



