CLASSES OF PLANTS 



441 



15. Sumac family. Some of the sumacs yield tannin; otherwise the 

 family is noticed by most people as a nuisance, because of the poison ivy 

 and the poison sumac. 



16. Maple family. The maple is valuable as hard wood and is still a 

 considerable source of sugar. 



17. Grape family. Though a small family in number of species, the 

 grape family has many varieties. The fruit is the basis of many kinds of 

 wine as well as of soft 

 drinks, and is used increas- 

 ingly in this country in the 

 dried form, as raisins. 



18. Mallow order. In 

 the cotton plant v^e have 

 the most important 

 single member of this 

 group, since it supplies 

 so large a part of the 

 world's clothing, besides 

 the valuable oil v^/'hich is 

 expressed from the seed. 

 A gum similar to traga- 

 canth is obtained from 

 the roots of the marsh 

 mallow. The linden 

 tree and the jute plant 

 represent another divi- 

 sion of this order. The 

 tons of chocolate and 



Fig. 182. The cotton plant (Gossypium) 



Many varieties of cotton are cultivated. New flow- 

 ers keep opening up as the old bolls ripen so that 

 harvesting goes on from July to November. The 

 fiber of the seed pod is used not only for thread 

 and cloth but for making celluloid, photographic 

 film, explosives, surgical dressings, and other things 



cocoa with which we 



enrich our candies and breakfasts come from the cacao plant. 

 The seeds, or "beans," are taken from the fleshy pulp and ex- 

 posed to a sweating, or fermentation, process and then dried in 

 the sun. This seed contains a large amount of fat (which is 

 used separately for soaps and for other purposes as "cocoa 

 butter") and of starch. It is thus a nutritive material and not 

 to be classed with such beverages as tea and coffee. These three 

 all contain the same alkaloid {theobromin, caffein, and thein 



