Texas golden gladecress Leavenworthia texana
ESA status: endangered

Texas golden gladecress pc Suzzanne ChapmanThe Texas golden gladecress is a member of the mustard family, with petite golden yellow flowers and dark green, succulent stems and leaves. This pretty annual flower has been a candidate for listing since 1990; the U.S. Fish and Wildlife Service ranks it among the top 40 most imperiled species on its candidate list and is at long last proposing it for listing under the Endangered Species Act (ESA). The plant is a habitat specialist that grows only in ironstone outcrops of the Weches Geologic Formation in east Texas: open, sandy, alkaline glades created by ancient seas 30 to 50 million years ago. Although relatively small and surrounded by oak-hickory-pine forests, the Weches outcrops support highly diverse plant communities, including rare and endemic species that specialize in these unique environments.

All known gladecress sites and remaining habitat are on private land. Some sites are so small that they are measured in meters: the Geneva site (Sabine County) is approximately 9 square meters. The largest population, an introduced population of gladecress occupying about 18 square meters on a farm in Nacogdoches County, was eradicated by a pipeline installation in 2011, leaving only about 400 plants in three populations.

The Texas golden gladecress generally shares its habitat with the white bladderpod (Lesquerella pallida), which is listed as “endangered” under the ESA. However, when a species’ habitat is measured in meters, it is not enough to hope that the gladecress will be saved as a coincidence of conservation measures intended for the bladderpod. Indeed, habitat loss continues to drive the gladecress to the brink of extinction; quarrying of glauconite, oil and gas wells, and the associated roads and pipelines have destroyed 50 percent of the known populations as of 2011. Glauconite is in high demand as an ingredient of road beds, well pads, and fertilizer. The entire range of the Texas golden gladecress is underlaid with natural gas-bearing shale, which is being rapidly developed. Invasive species outcompete the small plant for light and nutrients. The gladecress is truly in dire straits, and Guardians is working to ensure its future. 

photo credit: Suzzanne Chapman