Mount Diablo Buckwheat Critically Endangered Wildflower Discovered Near Antioch

Thanks to a team of botanists contracted by the East Bay Regional Park District (EPRPD), the endangered Mount Diablo Buckwheat was identified as thriving at Black Diamond Mines Regional Preserve in Antioch, California.

Save Mount Diablo board member Heath Bartosh, (left) and Brian Peterson (right) amidst a field of rare Mount Diablo Buckwheat wildflowers that they rediscovered in May of 2016. This location is being kept a secret to protect the species.

Heath Bartosh, a botanist and member of Save Mount Diablo’s Board of Directors, came across the wildflower in May 2016, along with colleague Brian Peterson of Nomad Ecology.

When the beautiful wildflower was rediscovered in 2005 at Mount Diablo State Park by UC Berkeley graduate student Michael Park— after being thought extinct for 69 years — we thought there were only 20 plants at a single spot in the entire world.

Locating the plant has been “the holy grail” for East Bay botanists and news of the rediscovery spread quickly.

Save Mount Diablo is a member of the Mount Diablo Buckwheat Working Group which has been actively searching for the rare plant since it was first rediscovered at Mount Diablo in 2005.

After the 2005 rediscovery, seeds were collected and camera traps installed to monitor the wild population. Beginning in 2006, plants were propagated at UC Botanical Garden at Berkeley. Seeds are stored in multiple seed banks. Efforts made to increase the population at Mount Diablo have been challenging, but were successful in increasing numbers even during repeated years of drought. The discovery site was kept secret to protect the species.

Habitat was mapped and explored over the next ten years but no additional populations of the plant were found. There was just one location for the critically endangered plant, on the brink of extinction, with just 100-200 plants.

Close up image of the Mount Diablo Buckwheat (Eriogonom truncatum), 2016. Locating the plant has been “the holy grail” for East Bay botanists.

Until this May, when the two botanists found a second population. Unlike the sparse population of 100-200 plants at Mount Diablo, the new discovery site was estimated to include approximately 1.8 million plants—but in just two patches totaling a half acre.

“I’m so thrilled to share this news, it’s the find of a career.”  said Bartosh. “The most recent records of Mount Diablo Buckwheat are from chaparral edges on Mount Diablo.

But early California botanist William Brewer, the original discoverer, found it on dry hillsides near Marsh Creek. We recorded this species growing in grassland on highly erosive soils, most likely the same type of habitat Brewer observed.

The new information will hopefully lead to the discovery of other new populations.”

“Finding the Mount Diablo Buckwheat in Black Diamond Regional Preserve is exciting,” said Matt Graul, Chief of Stewardship at EBRPD. “The locations are being kept secret to protect the endangered plant and the working group waited until the plants have gone to seed to announce the discovery.

The Park District takes our responsibility to be good stewards of this rediscovered treasure incredibly seriously.”

“This plant is so rare botanists haven’t been sure where to look”

“This plant is so rare botanists haven’t been sure where to look,” said Seth Adams, Land Conservation Director for Save Mount Diablo. “Many references still suggest the species is extinct. On the one hand a second location is good news, but it could be dramatically affected by East County development pressure.

Right now, for example, Antioch is considering plans for more than 4,000 houses.”

“The Antioch population habitat is quite different from the 2005 rediscovery site, and provides valuable information for efforts to develop new populations,” said Holly Forbes, Curator and Conservation Officer at UC Botanical Garden at Berkeley. “Our efforts to propagate this species at the Botanical Garden and to protect seeds in seed banks are insurance against natural disaster in habitat.”

Close up image of the Mount Diablo Buckwheat (Eriogonom truncatum), 2016. Locating the plant has been “the holy grail” for East Bay botanists.Save Mount Diablo co-founder Dr. Mary Bowerman collecting samples from the mountain, 1932. Dr. Bowerman recorded Eriogonom truncatum in 1936, the 6th of only 7 known findings (until now). The last known sighting of the Mount Diablo Buckwheat was recorded in 2005.

Eriogonom truncatum was first recorded on May 29, 1862 by William H. Brewer on the Mexican rancho acquired by Dr. John Marsh. Over the next 78 years the Mount Diablo Buckwheat was recorded a total of seven times. The second last recording was in 1936, by botanist Mary Bowerman, who later became co-founder of Save Mount Diablo.

Since then Eastern Contra Costa has become a nationally recognized biodiversity hot spot for rare species.

The good news is that thousands of acres there have been preserved.

However the area is also threatened by rapid development. Discovery of a second population of the Mount Diablo Buckwheat edges the species back from the brink of extinction.

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