HITCHCOCK — PLANTS OF AMES, IOWA. 48 I 



nas, etc. The portion in the angle formed by the junction of 

 Squaw creek and Skunk river is called "The forks." 



There yet remains to be spoken of, the habitat of water-plants. 

 A few can be found in the streams, but the greater part are only 

 found in still or slow-flowing water. The nearest lakes are Cairo 

 lake and the walled lakes of Hamilton county. Besides these 

 there are ponds, of which there are two kinds : First, those which 

 have muddy banks and water, and which are often bayous from 

 the streams ; in these scarcely any vegetation grows. The second 

 class is found in depressions in the prairie. The vegetation is 

 very dense, and the bottom is of peat. Here will be found water- 

 lilies, pond-weeds, and Utricularia. Formerly these prairie 

 ponds were very numerous, but the extensive system of drainage 

 employed of late years, and the series of droughts from 18S4 to 

 1SS7, have caused them to almost disappear. For this reason many 

 water-plants, which were abundant a few years ago, have been 

 marked in the catalogue as "becoming rare." During the sum- 

 mer of 18S9 I was unable to find a single specimen of Castalia 

 tubcrosa. Utricularia vulgaris, Pontederia cordata. and a num- 

 ber of other aquatics, though I collected them frequently five or 

 six years ago It is for this reason, chiefly, that plants from 

 Cairo lake are included, as the excursion was made for water- 

 plants. 



On the other hand, introduced species become established in 

 our flora, and may soon become a constituent part. Lactuca 

 Scariola is an example. Within a few years this species has in- 

 creased to a marked extent. Solarium rostratum, now common 

 in Southwestern Iowa, will undoubtedly reach Story county in 

 a few years. 



It is hoped that the following catalogue may be of value as a 

 record useful in studying the changes in the flora of which 

 it treats. 



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