Federal officials are trying to save a plant called San Diego ambrosia. An environmental group sued to protect the habitat of the endangered herb.
The small blue gray herb is known to exist only in San Diego and Riverside Counties and Baja, Mexico.
It's normally found on flat or gently sloping grasslands and on the upper terraces of river drainage basins.
But the ambrosia's habitat has been threatened by urban sprawl.
The U.S. Fish and Wildlife Service designated 783 acres of San Diego and Riverside counties as critical habitat for the ambrosia.
The Center for Biological Diversity sued to get the designation.
"For the San Diego ambrosia that is already teetering on the brink of extinction, identifying and protecting key areas is crucial to its survival," said Center for Biological staff attorney Jonathan Evans.
He said native plants and animals are part of Southern California's heritage.
"And it's important for San Diegans to know that they can go out and find these native species that are still around even though they're subjected to a great amount of threats," said Evans.
Evans said while the San Diego ambrosia ranges from Baja to Riverside County, it's been found in coastal sage scrub areas and near Santee.
