LAUSR

Abstract The late-winter ephemeral Leavenworthia exigua var. lutea (Tennessee Gladecress; Brassicaceae), has historically been known from moist limestone and dolomite cedar glades in Tennessee and Alabama. Until this study, its distribution included only 8 glades in 6 counties of the Valley and Ridge, Appalachian Plateau, and Interior Low Plateau physiographic provinces in Alabama. During early spring of 2017, 2018, and 2019, we examined 26 Alabama glades for the presence of this very rare taxon. The historic populations in Jefferson and St. Clair counties of central Alabama have been extirpated by habitat destruction from urbanization. The population of L. exigua var. lutea reported from Colbert County (northwestern Alabama) could not be relocated, while that in Lawrence County (north-central Alabama) was found to be based on misidentified specimens of L. alabamica (Alabama Gladecress) with yellow flowers. This study documents 9 new records of L. exigua var. lutea in Shelby and Sumter counties, more than doubling the known populations in Alabama and extending its distribution into the Gulf Coastal Plain.