SAN LUIS OBISPO, Calif.—An endangered California pine shrub is not out of the woods yet.

The U.S. Fish and Wildlife Service said Tuesday that the Indian Knob mountainbalm, which grows in San Luis Obispo County, will not be removed from the endangered species list as previously recommended.

The coastal shrub was declared endangered in 1994.

In 2009, after threats like development, oil drilling and mining were reduced in the areas where it grows, federal officials recommended downgrading the mountainbalm to a threatened species.

But new threats now come from other plants, primarily invasive grasses not native to the area like perennial veldt grass.

Officials were unable to find previously documented new growths of the mountainbalm in recent studies, and decided the likelihood of extinction is enough to keep it on the endangered list.