38 The Water Supply of Minneapolis — Committee. 



and its occurrence here is rather remarka])le. So many plants pe- 

 culiar to the great plains give this place a remarkable aspect, more 

 so as the vegetation surrounding the ledge on all sides is the ordi^ 

 tiary prairie flora. In the shallow stream, called Pipestone creek, 

 large ni isses of the interesting liverwort Riccia fluitans, Z. were 

 found, but none that were fertile. 



Among the rare plants from Blue Earth Co., may be men- 

 tioned wolffia Columbiana, Kasten. This plant occurs in a small 

 pond near South Bend. The pond is a part of an old, abandoned 

 channel of the Blue Earth river and is hemmed in on all sides by 

 high bluffs . Here the wolffia occurs in great abundance, form- 

 ing a stratum on the surface of the pond from one to two inches 

 in thickness during the hot summer months. It has not yet been 

 found in flower in this locality, and is doubtless an immigrant from 

 localities further south, though it must have existed in this par- 

 ticular pond for many years, judging from the great masses of de- 

 composed wolffias that have accumulated around the borders of 

 the pond. 



Blue Earth Co. is very rich in different forms of characeae. 

 Five species were met with though no special search was mude 

 for them. They were as follows: 



Nitellaflexilis. 



Chara foetida. 



C. frag His. 



C. contraria. 



C. ? 



This latter has not yet been determined and may prove to be 

 an undescribed species. The attention of our botanical collectors is 

 called to this interesting group of plants. There are doubtless 

 very many species of these plants within the borders of the state 

 and a systematic search cannot but be rewarded with the discov- 

 ery of many as yet, unknown species. 



March 6, 1883. 



[Paper C.^ 



Minneapolis, Minn., March 0, 1883. 

 Mr. Chairmais^: — 



The committee appointed at the last meeting of this Academy, 

 to investigate and report on the subject of the water supply of 

 the City of Minneapolis, now offer their report. 



