Chapter XXIII. 



Grasses and Sedges, 



The third order is not represented in Minnesota, but the 

 fourth order, which inchules the grasses and sedges, is alnni- 

 dantly represented by a large variety of forms. There are in 

 the state about i6o different species of grass and about the same 

 number of sedges. 



Grasses. Grasses are characterized by their hal)it of forming 



the sort of fruit wliich is 

 termed a grain. They are, in 

 Minnesota, all of them annual 

 or perermial herbs, but in In- 

 dia and the Orient some va- 

 rieties become large trees, in 

 which conditio n they are 

 termed bamboos. The stems 

 are for the most part hollow, 

 the leaves slender and sheath- 

 ing, though some panic grass- 

 es have broad lea\es — or even 

 ovate leaves in certain foreign 

 species. The llowcr clusters are generally spikes composed of 

 little spikes known as spikclcis. In the flower clusters and 

 flowers, the leaves are developed as chaffy scales and the flowers 

 themselves lack any colored perianth. There are usually three 

 stamens and the ovary has but one cavity producing but a single 

 seed. The ovary is conceived to consist of one carpel, the other 

 two having disappeared. The branched stigma on top of the 

 rudimentary fruit is feather-like, and for its pollination the chief 

 agent is the wind. The ripened fruit inclosed in its chaffy 

 scales is called a grain. The seed inside the grain is not sep- 

 arate but fills up the fruit-cavity so that the whole is one solid 



Fig. 82. wild rice and pond lilies. .A.fter 

 photograph by Williams. 



