Environmental Description:  This calcareous riverside seep community occurs along sections of river shoreline where winter ice-scouring, limestone outcrops, and natural seepage co-occur. The substrate is alluvial deposits combined with cobbled substrate in which weathered bedrock has been broken into distinct rocks of various sizes. The seeps are generated in areas where groundwater flows out and over the cobbled substrate, supporting many calciphiles and rare species. Winter ice-scour that removes tall vegetation and woody plants maintains predominantly herbaceous vegetation. The early-successional floristic assemblages include species able to regenerate from buried rootstocks or from seeds dispersed along the shoreline. Seasonal and annual variation in water levels is another important process affecting the vegetation. Typically, sites have a north-northwest exposure and are fully exposed to late-day sun. The slope of the outcrops ranges from a gentle incline rising from the river shoreline to a 28° incline at the most steeply sloped sites.