Rare wetlands plant that grows in Arizona listed as endangered

A rare plant that depends on wetlands for survival is now on the federal endangered species list, a designation that environmentalists say will boost efforts to protect the last free-flowing river in the desert Southwest.

The U.S. Fish and Wildlife Service published the decision Friday in the federal register to list the Arizona eryngo as endangered and set aside nearly 13 acres in southern Arizona as critical habitat.

The decision comes years after environmentalists petitioned and then sued to gain protection for the plant with cream-colored spherical flower heads. Only two populations are known in Arizona — near Tucson and in the San Pedro Riparian National Conservation Area.

The eryngo grows in ciénegas, a type of wetland fed by natural springs that come from the deep aquifer and nourish the San Pedro River. The plant’s habitat and the flow of the San Pedro River have been threatened by over-pumping of groundwater in the region, climate change and drought.

“This gives us a new ability to protect it,” said Robin Silver of the Center for Biological Diversity.

The plant also is found in the northern Mexican states of Chihuahua and Sonora. It historically grew in southwestern New Mexico but hasn’t been documented there since 1851, the Fish and Wildlife Service said.