Thread-leaved brodiaea is a perennial herb, or bulb, in the asparagus plant family (Themidaceae). It was listed as threatened in 1998 due to loss of habitat from urbanization and agricultural conversion, livestock grazing, off-highway vehicle use, fire suppression activities and non-native plants. The species benefits from multiple conservation plans that have been implemented since its time of listing, to include the Northwest San Diego County Multiple Species Habitat Conservation Plan City of Carlsbad Subarea Plan, Orange County Southern Subregion Habitat Conservation Plan and Western Riverside County Multiple Species Habitat Conservation Plan, which work to minimize and mitigate the loss of the species and its habitat. In addition, the species is protected and, or managed, on federal lands with the National Forest and Marine Corps Base Camp Pendleton.