Plants typically occur in clumps where they arise from fleshy bulbous bases. Currently, only seven populations are known to be extant, consisting of five sites in Lewis County, Tennessee, and one site each in Bartow County, Georgia, and Franklin County, Alabama.
Population size ranges from a few dozen plants at one site to thousands of individuals at two sites.
Most sites support populations of a few hundred plants and each site occupies less than an acre in area. An historical record exists for Gordon County, Georgia. Xyris tennesseensis occurs in seep-slopes, springy meadows, or on the banks or gravelly shallows of small streams. As with all Xyris , the habitat is open or thinly wooded and the soils are moist to wet year-round. However, this species differs from other Xyris in being found in areas where calcareous rocks are at or near the soil surface.