GRASSES OP IOWA. 161 



the higher altitudes of the Rocky mountains and other ranges. 

 In most localities south of Pennsylvania, Minnesota and 

 Oregon, two or more crops may be harvested in a single sea- 

 son.'' 



jiice. — The early varieties of rice mature in from 100 to 120 

 days the late varietes from 150 to 200 days. They require a 

 mean temperature of 55° F., summer varieties of 71*^ to 89° F., 

 being an average mean of 68° F. Rice culture is most suc- 

 cessful in tropical and sub-tropical regions, although it has 

 succeeded as far north as 38^^ north latitude in Illinois, but its 

 culture is nearly abandoned in that state. Its general successful 

 commercial culture in the United States does not extend much 

 beyond 34° alorg the Atlantic coast, and then again exten- 

 sively along the Gulf coast. Koernicke states that its latitude in 

 Europe is -45°. Its general culture in Asia occurs in Corea, 

 Japan and China. Simmonds says: "One of tbe most exten- 

 sively diffused and useful of grain crops, and supporting the 

 greatest number of the human race, is rice. It occupies, in 

 fact, the same place in most tropical regions that wheat does 

 in the warmer parts of Europe, and oats and rye in those more 

 to the north. It is raised in immense quantities in India, 

 China, Java and most eastern countries, in parts of the West 

 Indies, Central America and the United States, and in some of 

 the southe'n countries of Europe. The chief food of perhaps 

 one-third of the human race, it affords the advantages attend- 

 ing wheat, maize and other grains, while it is susceptible of 

 cultivation on land too low and moist for the production of 

 other useful plants.'' 



Grasses in Medicine. 



Quack grass. — But few of the grasses are used in medicine. 

 One of the best known of the grasses used in medicine is quack 

 grass {Agropyron repens). The root is taktn in the form of a 

 dec .action and is a useful remedy in suppression of urine and 

 vesical calculus. The drug is still much used in France, where 

 it is used for the discharge of mucus from the bladder. 



Lemon grass. — The lem n grass oil or citronella oil is derived 

 from several species of the genus Andropogon. The A. Nardus 

 is a native of Ceylon atd Hindoostan. The A. citratus or lemon 

 grass oil of verbena is jikewise cultivated in Ceylon ard Sin- 

 gapore and is native to the same general region. Another 

 species, A. schoenanthus, is native to northern and central 

 U 



