

THE PLANTS OF WINNESHIEK COUNTY 147 



THE PLANTS OF WINNESHIEK COUNTY. 



BY B. SHIMEK. 



Winneshiek county presents a flora of unusual richness. Both 

 because of its geographic position and its varied surface features 

 it offers conditions which have made possible the development 

 of a variety of plants scarcely equalled in any other county of 

 the state. Its northerly position and its rough topography, 

 especially along the Upper Iowa or Oneota river have brought 

 a northerly flora, such as belongs to the heavily wooded regions 

 of Minnesota and Wisconsin ; its wooded knobs and ridges along 

 the Turkey and the head waters of the Yellow rivers remind one 

 of the rough wooded areas of southern Iowa ; while the prairies 

 are but a continuation of the greater prairies of the west. Each 

 of these territories presents a variety of conditions. The 

 roughest includes the driftless area and the drift border, with 

 their deep gorges with narrow alluvial bottoms, their exposures 

 of both sandstones and limestones, their shaded mossy banks 

 and wooded slopes with not infrequent small bogs, and their 

 drier wooded ridges with occasional treeless barren summits ; the 

 more southerly timbered ridges present somewhat similar con- 

 ditions, but without the prominent rock-exposures, and with 

 floral areas less sharply defined than those which characterize a 

 region cut by deep gorges ; and the treeless areas include both 

 the rich level prairie and the prairie bogs of the Iowan drift, and 

 the more rolling and drier prairie of the Kansan. The soils are 

 derived chiefly from loess and drift (which are discussed else- 

 where in this report), and therefore vary comparatively little in 

 chemical composition. Occasionally coarser, sandy material 

 appears on the ridges, but on the whole a finer soil prevails. 



