Dec. 10—A wildflower found on fewer than 30 acres near the southern border was given endangered species status Wednesday by U.S. Fish and Wildlife.
The swale paintbrush grows 19 inches tall and flowers in pale yellow. It can only be found in approximately 28 acres of Hidalgo County, all on a piece of private property in the Animas Valley. Swale paintbrushes also have been found in Chihuahua and Durango, Mexico, but there has not been a verified sighting in Mexico since 1985.
“Almost everything you love is made of plants,” Katie Sandbom, biologist at New Mexico’s Ecological Services Field Office said in a statement. “They create habitat and support wildlife and pollinators. Rare plants, such as the swale paintbrush, make New Mexico’s biodiversity amazing.”
The agency is encouraging New Mexicans to report sightings of the rare plant to Sandbom via email at katie_sandbom@fws.gov.
Environmental advocates asked Fish and Wildlife to designate critical habitat status for the species, because critical habitat has proven to be a powerful conservation tool, said Michael Robinson, a senior conservation advocate for the Center for Biological Diversity, which petitioned to list the species.
But critical habitat designation also requires publishing the plant’s precise location, and Fish and Wildlife decided against it to reduce the risk of seed-gathering or habitat damage from illegal collectors, according to a news release.
The swale paintbrush’s limited distribution makes it inherently vulnerable, Robinson said.
Threats to the species’ survival include habitat loss, altered hydrology affecting surface water the plants rely on, climate change, drought, exotic plant invasion and overgrazing by livestock, according to Fish and Wildlife.
Mark Egger, a retired science teacher and research associate at the University of Washington Herbarium , is also worried about the swale paintbrush population’s proximity to the U.S.-Mexico border wall. He’s concerned any new construction on the section of border wall near the plant population could endanger it.
The swale paintbrush is a member of the Indian paintbrush genus. There are over 200 species of Indian paintbrush, also known as Castilleja. Castillejas, which Egger had studied for decades, are hemi-parasites, which attach themselves to the roots of other plants for nutrients but also photosynthesize, flower and seed on their own.
Most of the species in North America are perennials that grow throughout the entire year. The swale paintbrush is an annual, so it must grow from a seed each year.
For much of the year, the swale paintbrush is not visible. In some drought years, researchers have only found four or five plants, whereas in years with heavy rain, they have found thousands, Egger said. Recently, the decline has been apparent. Researchers have only reported a few plants or a couple hundred, he said.
Recovering the species will require looking for similar habitats in the Southwest where a new population of the plant could be started, Egger said, and studying the places the swale paintbrush has grown in Mexico to see if the plant is still there.
U.S. Fish and Wildlife has committed to working in collaboration with conservation partners in Mexico to bring the species back from the verge of extinction, Regional Director Amy Lueders said in a statement.
“They also need to understand more about the ecology of the plant, like what brings about the germination? Why is it only seen some years and in large numbers, and other years in very low numbers — all those ecological variables that we still only have the bare-bones understanding of,” Egger said.
A photo of a swale paintbrush was posted at a location in Chihuahua this fall. It was the first evidence since the 1980s that the plant still could exist in Mexico.