OLD LAKE VEGETATION IN HAMILTON COUNTY. IOWA. 



By L. H. Pa mm el. 



THE name drift has been applied to the mixture of clay, sand, 

 gravel and boulders found in many parts of the State. The 

 Iowa drift is largely of glacial origin, there being two well-de- 

 fined sheets. The lowest is a part of the great mantle extend- 

 ing over the northern United States, while the later drift, known as 

 the Wisconsin, forms a triangle, with its apex reaching Des Moines. 



It is in this area that these lakes occur. The water is generally 

 of surface origin, and is held because of the highly retentive clay. 

 Owing to cultivation and the drainage, many of the small lakes have 

 disappeared, but before cultivation these lakes were extremely common 

 throughout this part of Iowa. These are indicated on many of the 

 old surveys where they are outlined. 



The lake here to be described covers on area of 200 acres in the 

 vicinity of Jewell Junction. A quarter of a century ago it was 

 covered with water from one to three feet over the entire area. Now, 

 however, water only remains in this lake up to the middle of July, 

 while some portions carry a slight amount of water the entire year. 

 The shore lines of this lake show small boulders. Beyond the imme- 

 diate shore lines, the countr}^ rises gradually, attaining an elevation 

 approximately of fifty to seventy-five feet. The lake is situated in a 

 pocket. The subsoil is a tenacious clay, the surface is 'a black, peaty 

 soil which is very retentive of moisture. As might be expected, the 

 vegetation is of a heterogeneous character near the shore lines. 

 Many plants are of mesophytic character. 



The flora of the lake is interesting as showing a marked zonal dis- 

 tribution and a gradual displacement of the original inhabitants. The 

 great body of the lake-bed is covered with Cat-tails {Typha latifolia) 

 from four to six feet high. Towards the northwest in proximity to 

 the two islands, water was standing early in September. In consider- 

 ing the plants, we may begin the area where the water occurs in small 

 pockets, earlier in the season. At this time of the year, however, it 

 is nothing more than a beach or strand. 



Outer Beach. The most characteristic plants of this beach are 

 Paniciim criis-galli, P. capillar e, Calamagrostis Canadensis, Carex sp., 

 EleocJiaris palustris, Lobelia syphilitica, Asclepias incarnata, Lycopus 

 sinuatus, great masses of Scutellaria galericulata, Solidago scrotina, 



