Trillium discolor, the mottled wakerobin, pale yellow trillium, or small yellow toadshade, is a species of flowering plant in the family Melanthiaceae. It is native to areas of the Savannah River drainage system of Georgia, North Carolina and South Carolina such as Steven's Creek Heritage Preserve and Lake Keowee. It is found along moist stream banks in upland woods, on acidic to basic soils.
Trillium discolor is a perennial herbaceous plant that blooms mid April to early May. It has a flower with pale yellow petals that stand upright at the junction of the three leaf-like bracts.
Trillium discolor is ranked as globally vulnerable (G3) due to its restricted geographic range and ongoing population decline.
The species is endemic to the Savannah River drainage of Georgia, North Carolina, and South Carolina, with an estimated range of approximately 5,000âÂÂ20,000 kmò and 81âÂÂ300 known occurrences. Long-term population trends suggest a decline of approximately 10âÂÂ30%, partly due to historical habitat alteration such as dam construction and ongoing land-use changes.
Major threats include habitat loss from commercial and residential development, silvicultural practices, and hydrological changes, as well as competition from invasive plant species such as Ligustrum sinense and disturbance from feral hogs. Herbivory by white-tailed deer may also negatively impact populations, particularly smaller occurrences.
More broadly, many species of Trillium are particularly vulnerable to disturbance due to their slow life history, delayed reproductive maturity, and limited seed dispersal. These traits, combined with habitat fragmentation and localized endemism in the southeastern United States, contribute to elevated conservation concern for narrowly distributed species such as T. discolor.