126 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



the river, which extend for considerably more than a mile in a 

 general north and south direction. These ponds furnish the only- 

 resort of any size in the county for waterfowl, and the mud 

 flats exposed by the summer evaporation attract thousands of 

 sandpipers during the fall migration. 



Practically the entire county outside the flood plain of the 

 Iowa and its tributaries* is under cultivation, and consequently 

 little of the original prairie flora and fauna can be found undis- 

 turbed. Much of the timber and underbrush has been cleared 

 along the streams, leaving open wooded pasture land, and con- 

 sequently here, too, it is difficult to find any large area in wliich 

 original conditions are preserved. 



Most of the timber is second growth and not of large size. 

 Some beautiful specimens of oak of various species, elms, and 

 one or two black cherries still stand in the Marshalltown ceme- 

 terv. however, and at various places at the north end of the city. 

 Frequent groves of giant cottonwoods can be found along the 

 Iowa river and some other streams. Perhaps the largest area 

 of wild land remaining within the limits of this county is along 

 Mormons Ridge, which lies along Iowa river, northwest of the 

 towii of Albion. It is well wooded and somewhat rugged, and 

 this probably accounts for its present condition. 



The following list of trees and shrubs, while by no means com- 

 idete, contains the more common forms growing along Iowa river 

 and tributary streams (nomenclature from Grray's New ]\Ianual 

 of Botany, 7th edition) : 



Red cedar, Juniperus virginiana Linnaeus. Occasional on the bluffs 

 along the river. All small. 



Green brier, Smilax rotundifoJia Linnaeus. Common in the bottom 

 land. 



Bla"k willow, Salix nigra Marshall. Common. 



Sandbar willow, Salix longifoUa Muhlenberg. Common. 



Salix missouriensis Bebb. (?) 



White poplar, Populus alba Linnaeus. Occasional as an escape; com- 

 mon in cultivation. 



Aspen, Populus tremuloides Michaux. Tolerably common on the hill- 

 sides. 



Cottonwood, Populus deltoides Marshall. Probably the dominant low- 

 land form. 



Butternut, Juglans cinerea Linnaeus. Common on the flood plain of 

 Iowa river. Occasioifiil on the upland. 



Black walnut, Juglans nigra Linnaeus. Common with -7. cinerea. 



'For a full discussion of these tributaries see Beyer, op. cit.. pp. 2n.;-20S. 



