BOISE, Idaho (AP) — A small, flowering plant found only in southwest Idaho will again be listed as threatened under the Endangered Species Act.
The U.S. Fish and Wildlife Service on Monday announced the listing of slickspot peppergrass to take effect Sept. 16.
The plant was originally listed in 2009, but Idaho Gov. C.L. "Butch" Otter filed a lawsuit challenging the listing that could have ramifications for cattle grazing on public land.
In August 2012, a federal judge vacated the listing and ordered Fish and Wildlife to more clearly define what "foreseeable future" meant when discussing threats to the plant.
The agency in 2014 held comment periods on the definition of "foreseeable future" as well as the agency's determination that the species needed federal protection. It used those comments leading up to the most recent decision and defined foreseeable future as at least 50 years — a span in which current threats could push the plant toward becoming endangered.
Otter spokesman Jon Hanian said the governor's office was still looking into Fish and Wildlife's decision and wasn't prepared to comment.
The next step in the process for Fish and Wildlife is determining the critical habitat for the plant that produces white flowers and can grow to 16 inches, though on average is 2 to 8 inches high. Scientists say the plant is found in small micro-habitats.
"These are unique habitats that are likely no longer being formed due to climate conditions," said Kim Garner, Fish and Wildlife's chief for classification and recovery in Idaho.
The ramifications of the listing are not clear. Federal agencies managing land where slickspot peppergrass is found will have to consult with Fish and Wildlife about uses for those areas. Scientists say the plant is found in only eight southwest Idaho counties.
"Those are eight counties where grazing goes on, so it still becomes significant to that part of the world," said John Freemuth, a Boise State University professor and public lands expert. "Where exactly is it and what uses are going on in that habitat? Those will now have to be reassessed, or even whether those uses will be allowed to continue because of the existence of that particular plant."
Matt Germino, a Boise-based research ecologist with the U.S. Geological Survey, said the slick spots the plant favors can be a foot to 10 feet in diameter. He said these micro-habitats are hard and crusty when dry but have a greasy, clay surface when wet.
"Hence the term 'slick spot,' " Germino said. "There really hasn't been much research on the ecology of the peppergrass or the slick spots themselves."
Slick spots have finely textured soil surfaces and appear to form as a result of local drainage, something noted during an unrelated study on soil erosion, he said. Their spacing is not uniform and can be somewhat clustered. Slick spots are generally found in flat areas, such as the Snake River Plain, but not in areas like the Boise foothills, he said.
Germino noted the plants use the slick spots, but it doesn't appear the plants do anything to help form them.
The plant is considered both an annual and biannual because under certain conditions it will continue thriving during the winter. But the plant can be vulnerable, Germino noted, because its short lifespan means the population needs to be renewed each year with seeds.
"One thing that is notable about this is that you've got a plant species that has a real affinity to a unique attribute of these landscapes," Germino said. "I think there's a lot to be learned from that. It means that template in that habitat really does matter."