Rare Arizona plant now on endangered list

Sweetwater wetlands.

Courtesy city of Tucson

A rare plant that depends on wetlands for survival is now on the federal endangered species list.

The U.S. Fish and Wildlife Service published a decision Friday to list the Arizona eryngo as endangered. The agency also set aside about 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.

Environmentalists say the decision will boost efforts to protect the San Pedro River, which is the last free-flowing river in Arizona.

The wetland plant depends on springs from deep aquifers that nourish the river and is threatened by the over-pumping of groundwater.