This grows in clumps in shallow running water in John's Mountain Wildlife management area in northwest Georgia. I only see this near the head of the creek drainage up in the hills and always in running water, never in the lower regions. It also grows many clumps where thick moss grows on the rocks with water running over them, especially where the grade is sufficient to prevent the mosses from being predated on by various species. It appears that these mosses form a prime soil substrate for this grass. I think it is predation (stonerollers and such) of these mosses that prevents it from growing in the larger sections of the creek further down. It has a small ridge all the way up the center of the blades and is fairly soft to the feel.