Center for Biological Diversity

For Immediate Release, March 3, 2021


Dr. Robin Silver, (602) 799-3275,

Endangered Species Act Protection Proposed for Rare Arizona, Mexico Wildflower

Arizona Eryngo Becomes First Species Protected by Biden Administration

TUCSON, Ariz.— In response to a petition from the Center for Biological Diversity and Maricopa Audubon Society, the U.S. Fish and Wildlife Service today proposed Endangered Species Act protection for Arizona eryngo, a critically imperiled wetland plant with only four surviving populations in Arizona and Mexico. The eryngo formerly also lived in one place in New Mexico but is now gone from the state.

The Service also designated 13 acres of critical habitat at the three confirmed surviving populations of the flower in Arizona: Agua Caliente and La Cebadilla, east of Tucson, and Lewis Spring in the San Pedro National Riparian Conservation Area.

The eryngo is at immediate risk of disappearing because of livestock grazing, overuse of groundwater, invasive species and climate change.

“Arizona eryngo and other irreplaceable parts of our natural heritage will be lost if excessive local groundwater pumping isn’t controlled, so we urge the Fish and Wildlife Service to immediately protect this imperiled flower,” said Robin Silver, a cofounder and board member of the Center for Biological Diversity.

The rare flower grows only in a specific type of permanently wet spring habitat called a cienega. Cienegas are a type of wetland unique to the Southwest, which provide crucial homes for fish, amphibians, invertebrates and migratory birds within otherwise arid landscapes.

More than 95% of cienega habitats have been lost. Both sites where this flower survives are threatened by overuse of groundwater to support sprawling human populations.

Arizona eryngo is imperiled along the San Pedro River as pumping lowers the groundwater table connected to the plant’s wetland habitat. The groundwater pumping overdraft in the Fort Huachuca-Sierra Vista area is more than minus 5,000 acre-feet per year. Recent hydrology studies predict the demise of the San Pedro Riparian National Conservation Area if the unsustainable pumping continues.

“Arizona eryngo is an indicator plant for the health of imperiled desert wetland habitats that many plants and animals rely on,” said Silver. “We’re glad to see the Biden administration protect this plant, but hope critical habitat is expanded to include areas where the eryngo can be recovered and not just the few places it is currently clinging to existence.”

Arizona eryngo is in the carrot family and can grow to be more than 5 feet tall, with large, cream-colored spherical flowers. It is also called ribbonleaf button snakeroot, and its scientific name is Eryngium sparganophyllum. The Arizona Native Plant Advisory Group ranks Arizona eryngo as one of the most endangered plants in the state.

Butterfly on Arizona eryngo. Photo by Elizabeth Makings. Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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