CHAPTER IV. 



Geographical Distribution of Grasses. 



Grasses are widely distributed over the earth's surface. Although 

 the species of the order are not so numerous as the Compositae, Legum- 

 inosae and Rosaceae, yet in number of plants the grasses outrank every 

 other order. Grasses are an important constituent of the meadows of 

 temperate and colder regions. A meadow has a very different aspect 

 than a plain or desert. In a meadow the grasses form an even turf made 

 up largely of a few species, among which are many of the most important 

 grasses like Poa and Glyceria. On the dry plains, savannas and steppes, 

 Stipa, Festuca and Andropogon predominate. Here the grasses grow in 

 bunches forming scattered tufts. Here the question is largely one of 

 obtaining moisture. Look where you will over the earth's surface, and 

 grasses occur. They are present in icy Greenland and in the Arctic and 

 Antarctic regions ; they are found at the very edge of the snow 'covered 

 mountains of the Rockies, the Andes, the Himalayas; they are abundant 

 in the tropical jungle, where they form impenetrable masses, like the 

 bamboos which are so common in China, Java, Sumatra and India. 

 forming a part of the tropical forest in the region of the Monsoon. 

 Species of grasses are much more abundant in the tropics than in tem- 

 perate or colder regions. The greensward is typical only in a country 

 where the ground is covered with a mantle of snow for a part of the year. 



The distribution of grasses may best be seen from an analysis of 

 some of the genera. The genus Poa, of which there are about one hun- 

 dred species, is found mostly in the 'northern temperate 

 and Arctic regions, but a few , of the species are also found 

 in colder, temperate regions of the Southern Hemisphere; a 

 few even occurring in the high mountains of the tropics. The 

 Poa pratensis is found in Europe and North America. The Poa 

 alpina in the arctic regions of America and Europe, and the high 

 mountains of New England and the Rockies. The Poa flabellata, the 

 largest grass of the genus, occurs in the Falkland and Fire Islands. The 

 Scolochloa festucacea, allied to Poa, is found from Emmet and Kossuth 

 counties through Minnesota, Dakotas, to Lake of the Woods and Sas 

 katchewan to the Peace River country, and in northern Europe and Asia. 



