286 NEBRASKA STATE HORTICULTURAL SOCIETY. 



tinct zone which may completely encircle the pond or lake. These plants 

 are very dark green, so that the belts of vegetation about the saline 

 lakes stand in marked contrast to the duller tones of the surrounding 

 hills. Still farther back beyond the zone of tall plants the shore vegeta- 

 tion of the saline lake passes either abruptly or gradually into the typical 

 wet meadow vegetation. 



The appearance of the fresh-water lakes is quite different. First of 

 all there is usually a wealth of submerged or half-submerged plants). 

 Some of these lakes are literally filled with great masses of pondweeds 

 (Potamogeton), and the water milfoil (Myriophyllum spicatum). The 

 bottom, in the shallower portions of such lakes, is covered with a carpet 

 of stonewort (Chara foetida, etc.), while the stems of the submerged 

 flowering plants are richly coated with algae of many kinds. In late 

 summer certain of these algae become broken away from their substrata 

 and float about on the surface of the water. During high winds at this 

 time great quantities of these, such as the net sack (Clathrocystis aeru- 

 ginosa), are washed on the beach in yellow green splashes. There are 

 also many very interesting animals iji the fresh-water lakes, a sponge 

 being one of the common forms. 



The white, encrusted beach is absent from the fresh-water lakes, as 

 also are the belts of salt-enduring plants. The commonest marginal 

 plant here is the great bulrush (Scirpus lacustris). Frequently this is 

 the only plant between the bunch-grass association of the hills and the 

 open water of the lake. Sometimes other species such as cat tail (Typha 

 latifolia), and the giant reed grass (Phragmites phragmites) occur in 

 mixture with the bulrush, or these may now and then form separate belts. 

 Wild rice grass (Zizania aquatica) is a common marginal or shallow- 

 water inhabitant of many of the lakes. This plant is about as tall as the 

 bulrush, but because of its leafy stems it often forms much denser stands 

 in the shallow water. When the seed is ripe every bed of wild rice is 

 a Mecca for thousands of water fowl that live in the vicinity of the lakes. 

 Wild ducks become so thick at times in these rich feeding grounds that 

 the noise they make reminds one of an over-stocked barnyard. 



The lakes range in size from small ponds to bodies of water one and 

 one-half miles wide hy five miles long. They vary in depth from four 

 feet to probably about fifteen. In many of the fresh water lakes the 

 vegetation is encroaching upon the water, so that in time all of the lakes 

 will have disappeared and wet meadows remain. The wet meadows of 

 to-day show this sort of an origin very plainly. Many stages in lake 

 eradication by invading vegetation may be seen in these lake regions. 

 Some lakes are quite free from submerged aquatic plants; others quite 

 free from bulrushes or wild rice; others show belts of these plants about 

 the shore; in others the bulrushes have begun to wander into the deeper 

 water, and in still older lakes the water can not be seen because of the 

 complete occupation by the bulrushes and other vegetation. The bul- 

 rush is the commonest pioneer in this succession, and it is well fitted 

 for this particular process. Oddly enough it is by the possession of the 



