150 



Aquatic Organisms 



the sunny shoals of muddy bayous about Ithaca and in 

 many places in New England. It covers the zone 

 between high and low water, creeping extensively over 

 the banks that are mostly exposed, and there forming 

 a most beautiful ground cover, while producing longer 

 leaf -stalks where submerged. These leaf -stalks carry 

 the beautiful four-parted leaf-blades to the surface 

 where they float gracefully. Fruiting bodies the size 



.; .- V/ 1 I&r"V. ^-^# ;;. "-jf. ^ ~j^^'~&a*;3*--ti-v i -' . >t 



*^^^S*J^?^i^n; 



^\":.i^ ' *T1^- >^A^"^^^^-.'-1 ' 



**&3*^:?\ J ^- 



FIG. 62. Floating plants: The largest branching colonies are Azolla; the 

 smallest plants are Wolffia; those of intermediate size are Lemna minor. 



Photo by Dr. Emmeline Moore. 



of peas are produced in clusters on the creeping stems 

 above the water line, often in very great abundance. 



Then there are two floating pteridophytes of much 

 interest. Salvinia, introduced from Europe, is found 

 locally along our northeastern coast, and in the waters 

 of our rich interior bottom lands the brilliant little 

 Azolla flourishes. Azolla floats in sheltered bogs 

 and back waters, intermingled with duckweeds. It is 

 reddish in color oftener than green and grows in minute 

 mosslike pinnately branched sprays, covered with 



