Riverwash Bedrock Prairie (Fall-line)

This grassy natural community makes its home on rock outcrops in rivers in the area between the Piedmont and Coastal Plain called the fall-line or fall zone. As the name implies, waterfalls and rapids are common as rivers leave the hard bedrock of the Piedmont and enter the softer sedimentary rocks of the Coastal Plain. Common species here are big bluestem, blue wild indigo, Indiangrass, and switchgrass—all of which are able to survive frequent floods and sparse soil

 This natural community is found from Virginia to Pennsylvania, in rocky, frequently flooded sites along rivers in the fall zone.

The range map shows the states in which this natural community has been documented.

More About This Natural Community

True to its name, the Riverwash Bedrock Prairie has the look of a prairie. Among the grasses, look for big bluestem, switchgrass, Indiangrass, and prairie cordgrass. Other low plants may include wild blue indigo, Indian-hemp, shrubby bushclover, golden ragwort, and obedient plant.

The rocky and flood-prone setting is not particularly welcoming to trees and shrubs. Floods and ice-scouring events can damage or even remove plants. Soil is sparse and mostly confined to cracks and small depressions in the rock. You may see some river birch saplings or silky dogwood, but they will likely be stunted.

For a more in-depth look at this community, click on a link under “Where to Explore It.”

Look for It in These National Parks

  • Chesapeake and Ohio Canal National Historical Park
  • George Washington Memorial Parkway
  • Harpers Ferry National Historical Park
  • New River Gorge National River 

Conservation Status

How vulnerable is a natural community? Is it at risk of elimination? Learn about conservation status.

Global Conservation Status: 
G3 – Vulnerable

Classification

Official names reduce confusion by providing a common language for talking about natural communities. Why so many names?

Common Name: 
Riverwash Bedrock Prairie (Fall-line)
Scientific Name Translated: 
Big Bluestem - Switchgrass - Blue Wild Indigo Riverscour Wet Meadow
Classification Code: 
CEGL006283