Rubble (Boulder, Cobble) Stream Bottom
Rubble (boulder, cobble) stream bottom communities are found in rugged, high-gradient streams primarily. These communities are generally inundated permanently. The bottom may consist of cobbles or small to massive boulders. The rock in these stream bottoms is often accumulated to considerable depths. These communities are usually nearly devoid of aquatic vegetation in most examples. A notable excpetion is found in the Emory-Obed River and Daddy's Creek systems where the highly invasive submerged aquatic plant Hydrilla verticillata grows abundantly in this community.