Trillium rugelii

Trillium rugelii occurs in the southern Appalachian Mountains. The species is locally abundant in parts of Georgia and North Carolina, but rare in other parts of its range. Its major threat is logging. Minor threats include deer, invasive species, and various types of development projects.

Trillium rugelii is found in mesic forests of the mountains and piedmont of North Carolina and Tennessee, south to Alabama, Georgia and South Carolina.

The number of occurrences is not known but there appear to be at least 80, based on herbarium specimens and natural heritage program data (SEINet 2019).

The species is occasionally threatened by deer and invasive species. Some populations are currently threatened by habitat alteration resulting mainly from silvicultural practices, commercial and residential development, and other construction projects.

Populations of T. rugelii occur on National Forest lands and private forests. The silvicultural practices in these areas should include precautions for these sites. Logging in areas occupied by the species is a significant threat as are utility rights-of-way. Increased sunlight from opening of the canopy and the subsequent drying of the soil has been noted to lead to the decrease in some populations of T. discolor (P. Shatley, pers. comm.). Trillium rugelii may respond favorably to increased sunlight in the short term, but increased soil drying will eventually reduce the habitat and the population. Increased sunlight, heavy erosion and sedimentation may preclude all but selective logging and care should be given to sedimentation control and avoidance of plants during logging.

Wild collecting for commercial trade is not currently a significant threat, although collecting for personal collections is a threat. Collection for scientific and educational purposes is sporadic and constitutes a negligible threat. Trampling is a concern with collecting and with some populations occurring near trails which receive heavy use. Relocation of the trail or placement of screening vegetation (native) may be needed if off trail use threatens or endangers the occurrence.

The extent of threats from exotic species is not known, however they are expected to displace the Trillium and compete for nutrients. Threats from aggressive ground covering plant species such as privet.

The impact of grazing by native fauna may be severe at some locations (T. Patrick pers.comm.). Deer tend to graze on the leaves and flowers. Predation may not have serious impacts on large populations but could severely impact smaller ones, although larger populations may attract predation. It is documented in other species that deer prefer flowering specimens and consecutive years of heavy deer browse reduces reproduction, partly by causing a regression to non-flowering single leaf plants: this leads to population declines, or potentially local extirpations (Augustine and Frelich 1998; Knight 2003; Rooney and Gross 2003; Webster et al. 2014). Opening sites to livestock grazing would have a serious negative impact on the species and its habitat. Grazing would impact the plants by both destruction of plants and disturbance to the soil and the nutrient input. Grazing may also promote the introduction of exotic species.