CHAPTER V 



HIGHER PLANTS 



Water Mosses and Seed Plants 



Compared with the number of higher plants which live on 

 land there are very few which live in the water. Most of 

 these bear their flowers above the surface though their leaves 

 and roots grow beneath it and they make up little groups 

 which are usually but fragments of large families that belong 

 on land. They live only partially in the water and are not 

 truly aquatic like the simpler plants. 



In most ponds the rooted plants (Fig. 21) grow from the 

 shore out to midwater and they vary greatly in the degree to 

 which they have taken on the ways of aquatic life. Close 

 to shore the arrowheads and pickerel-weeds (PL V) stand 

 upright with leaves and flowers a foot or more above the water. 

 A little farther out are plants which lean upon the water for 

 support; such are the yellow water-lily and the white one, 

 with pads and blossoms floating on the surface. Beyond these 

 plants, often among them, are featherj^ milfoils, Myriophyllum 

 and Elodea, and streaming pondweeds, the Potamogetons, all of 

 them submerged except for their flowers, which open in the air 

 and depend upon air currents or upon flying insects or upon 

 water to carry their pollen. Although these plants are largely 

 beneath the water, their reproduction occurs in the air. The 

 same thing is true of mayflies and other aquatic insects ; they 

 live in the water for a long time but they come out in the air 

 to mate and lay their eggs. 



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