Exploring Nature in the San Francisco Bay Area
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The Only Plant of Its Kind, Living Life in a San Mateo Agricultural Field

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ixteen years ago, a botanist and environmental consultant named Eva Buxton went to examine an agricultural field on the San Mateo County coast, where she found her attention drawn to a swath of small flowers, pinpricks of white and yellow in a sea of green. As she moved in for a closer look she saw that the delicate flowers had four white petals and eight yellow stamens. The color seemed almost to melt into the green foliage of the field.

Buxton says now that she doesn’t remember the time of day, or the weather, but she does remember the dawning realization that she’d found something unusual. The plant was clearly in the Limnanthes, or meadowfoam, genus. But meadowfoam flowers in California are pentamerous–that is, they have parts in fives. This one, Buxton clearly saw, had parts in fours. She rushed to consult the definitive reference book on California plants, the Jepson Manual, and found nothing. There were no known tetramerous meadowfoams in California.

Buxton contacted UC Berkeley botanist Dr. Robert Ornduff, a renowned expert on California native plants and Limnanthes in particular, and sent him a specimen. Ornduff knew of no tetramerous meadowfoams in the United States; after consulting a Canadian botanist he suggested that migrating birds might have dropped a few seeds of Macoun’s meadowfoam (Limnanthes macounii), an endangered tetramerous meadowfoam native to the Vancouver Island area in British Columbia. Buxton and Ornduff published a paper together in the “Noteworthy Collections” section of Madroño, the journal of the California Botanical Society, suggesting that the find might be a stray population of Macoun’s meadowfoam, and asking readers to keep an eye out for others.

But Ornduff grew Macoun’s meadowfoam and the new meadowfoam side by side in a common garden, and was able to tell Buxton that they were not the same species after all. The Canadian expert, Adolf Ceska, reached the same conclusion. Whatever this new plant was, Ceska told Buxton, it did “not fit exactly anything known in British Columbia.”

Before Ornduff died of melanoma in 2000, he sent a final email to Buxton that read: “This is a very interesting find; please stay on it.”

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otanists have repeatedly searched for evidence of tetramerous meadowfoams in California, going back to the 1970s, when, at Ceska’s suggestion, graduate students at UC Berkeley and UC Davis searched the state for Macoun’s meadowfoam. They found none, and ultimately concluded, Buxton wrote in a 2013 paper in Madroño, “that this species could not have been overlooked, if, in fact, it grew in California.” In the mid-2000s, a graduate student at Oregon State University spent four field seasons combing California and Oregon for tetramerous meadowfoams; he found none. In 2008 Buxton found three more individuals living in a field near Half Moon Bay, but by the next year those had disappeared, and they have not been spotted again.

The one field on the San Mateo County coast, it turns out, is the only known site where the four-part meadowfoam naturally appears.

In 2013, the plant was declared its own subspecies. Buxton, as its discoverer, chose to name it Limnanthes douglasii ssp. ornduffi, to honor the late Ornduff. Earlier this year, a forum of botanists associated with the California Native Plant Society agreed unanimously to classify Ornduff’s meadowfoam as a “1B.1” rare plant, making it eligible for endangered species listing in California and giving it protection under the California Environmental Quality Act.

And so the entirety of the world’s known natural population of Ornduff’s meadowfoam lives out its existence in an agricultural field on the San Mateo Coast. There are people around it all the time. Other plants come and go. The field gets plowed once a year. Somehow the meadowfoam persists. It pervades the field and nearby drainage ditches, and Buxton says it has only declined in population size by 10 percent since its discovery in 1998.

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n fact, says CNPS rare plant program assistant Daniel Slakey, Ornduff’s meadowfoam may have been able to survive all these years because of its placement. It is one of only two California plants that have their entire known ranges in a heavily human trafficked area (the other, Calystegia felix, is known only from landscaping in industrial, commercial and residential developments in Southern California). Some of the environmental factors influencing the plant’s future evolution will be inescapably human, Slakey says, which raises an interesting question: “At what point do we draw the line between a wild plant and a cultivated plant?”

“I don’t think anyone has a clear answer to this important question,” Slakey said in an email, “but it’s something we need to think about. I think the raising of this question makes a strong case for restoring populations of this plant in the wild, so that this plant will have a chance at experiencing natural selection again.”

Complicated questions also make saving the meadowfoam tricky. It’s the only naturally occurring population that anyone is aware of, so there’s a case for airlifting it, Franciscan manzanita-style, to safety in an undisclosed nature preserve. But Slakey and others who reviewed the plant’s life history decided that maybe some credit was owed to the process that let Ornduff’s meadowfoam thrive in the field in the first place. In a status review of the plant, Slakey, Aaron Sims, a rare plant botanist at CNPS, and Roxanne Bittman, a botanist at the California Natural Diversity Database, wrote: “given that the current management of the agricultural field has allowed subsp. ornduffi to persist since its initial discovery in 1998, and presumably for a much longer period prior to its discovery, CNPS and CNDDB recommend that the current management regime be continued.”

Or, as Buxton wrote in Madroño last year, “as repeated disturbance of the habitat of L. douglasii subsp. ornduffii appears to be the reason for the plants’ persistence in the agricultural field, no protective measures relating to this subspecies and its habitat should be necessary.”

In short, agriculture seems to work for the meadowfoam, so keep on farming. The landowner has communicated with the farmers to ensure that plowing and grazing remain the same. “The way they’re growing their crops, even if they switch up the crops, it’s important that they time their plowing to allow the plants to go all the way to seed so they can complete their life cycle,” Slakey said—not that there’s any reason to worry, he quickly added.

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s the population is monitored over the years, Slakey and CNPS hope to gather more knowledge about Ornduff’s meadowfoam and perhaps experiment more with its environment. Slakey suggested in an interview that it might be interesting for someone to take seeds to plant in different conditions to see what it can withstand and what it cannot.

In November 2010, Buxton went to check on the meadowfoam (she sometimes refers to it lovingly as “my plant”). There were early rains that year, and the farmer had already plowed the field.

“I thought, ‘Uh-oh, now he’s plowed all the seedlings under, and there won’t be any plants come spring 2011,’” she said. But sure enough, spring came and so did her plant. This meadowfoam has resilience!

The extra “.1” in the “1B.1” ranking means that the CNPS forum decided that 80 to 100 percent of the plants are severely threatened, Sims said. If a plant only grows in one place, which happens reasonably regularly, it always gets the .1 ranking. But Sims said this particular plant stands out: “That it only occurs in a non-natural environment represents a unique case for conservation,” he said.

While the plant seems to be doing fine, CNPS is putting together a seed bank for Ornduff’s meadowfoam, just in case.

“A natural disaster could wipe out an entire population, although we don’t necessarily see it going extinct,” Sims said. But because there is always a chance that the plant could die off naturally, for example if a genetic bottleneck occurs and it stops producing viable offspring, no one is taking any chances.

Buxton, the plant’s discoverer, has collected her own seeds. And she’s found at least one other place in the world that Ornduff’s meadowfoam seems to like: She continues to grow the plant in her home garden in Marin.

In San Francisco, A Dying Forest Waits for Action

Walk a few feet into the jungle on the west side of San Francisco’s Mount Sutro Open Space Reserve, and you’ll come to an unusual three-headed eucalyptus tree. Its single trunk is firmly rooted, and three trees sprout tenuously from the base, limbs stretching out away from the prevailing west wind and into the tangle of brown-and-green that dominates this 61-acre open space area.

We’re standing to the left of the trunk as a group of four cyclists pauses to study the Cerberus and debate their route. The apparent quirk of nature is an unexpected gift during their workout—they glance at the tree, they glance at their phones, they glance at the tree, they glance at each other, they glance at the tree.

Craig Dawson, meanwhile, just gazes at the tree. He stands at its base and surveys it and its surrounding plant life, gently probing the bark like a doctor searching for a diagnosis. To Dawson, who knows this place as well as anyone, the tree isn’t some kind of poetic, natural rebellion — it’s a sign that the forest is sick. The extra stress of multiple “heads” drains the tree’s main trunk of its water supply, turning what is referred to by Dawson as a “moisture sweet spot” into a stilled heart that will eventually give way to deep splits. Splits lead to breakage; breakage leads to limbs that crash to the ground with a sound Dawson likens to a clap of thunder. Sutro Forest is quickly becoming a hazardous place for hikers and bikers who want to escape the city without leaving it.

“If you hear something crack above you, just move quick,” Dawson says. “They call these falling branches widow-makers for a reason.”

Craig Dawson, executive director at Sutro Stewards, says that the forest cannot remain in limbo much longer without posing a real threat to its visitors. Photo by Becca Andrews.
Craig Dawson, the executive director of Sutro Stewards, says that the forest cannot remain in limbo much longer without posing a real threat to its visitors. (Photo by Becca Andrews)

Sutro’s once-thriving blue gum eucalyptus trees are dying for a variety of reasons, including age and drought, both of which make the trees more susceptible to disease, pests, and fire. And there are likely other causes yet to be identified by the master arborists and biologists studying the forest. But the foresters generally agree that time is running out for this urban forest, which is owned and managed by the University of California, San Francisco. At the moment, though, the university does not have an approved environmental impact report for maintenance, and in the absence of major work conditions are deteriorating fast. Dawson’s eight-year-old nonprofit, Sutro Stewards, has built and maintained trails through the forest, and performs some small-scale tasks, but the Stewards’ resources are limited. Attempts to come up with an updated management plan have stalled, so for now the Sutro Forest remains in limbo.

Until the late 1800s, the centrally located prominence that would soon be named Mount Sutro was covered in native coastal shrubs, grasses and wildflowers. It was most definitely not a forest. But Adolf Sutro, at the time the mayor of San Francisco, owned the hill, and a forest was what he wanted on his hill. So in 1886 he planted imported blue-gum eucalyptus and other fast-growing non-native trees  in honor of Arbor Day. Sutro’s efforts 130 years ago birthed the modern forest, which is problem number one: The typical life span of a blue gum eucalyptus in California is about a century, Dawson says. But that’s not Sutro’s problem any more. In 1895, Sutro donated 13 of Mount Sutro’s acres to UCSF, and the university bought another 90 acres that included the rest of the hill in 1953. Since then, UCSF’s relationship with the area, and its attempts to come up with a plan for it, have been complicated by the passionate voices of community members who have become invested in their local open space but who don’t necessarily agree on how it should be cared for.

The Sutro Stewards, along with a handful of master arborists, thought they had a workable plan in January 2013, when UCSF released a draft EIR that announced intentions to reduce the fire risk by thinning the forest and removing the dying eucalyptus trees. That plan, however, was met with fierce opposition from people who considered the removal of trees—any trees—as destruction of their beloved forest. The draft document received more than 300 comments, many of which argued that nature should be allowed to take its course in Sutro Forest. The uproar effectively stymied further action: In November 2013, the university announced that it was planning for a new EIR taking an entirely different approach and managing the forest solely for fire danger (mainly by bulldozing particularly dangerous areas); in February 2014, a university spokesperson said that that EIR had been withdrawn, and that work on the original draft EIR was continuing. UCSF’s website states that the delay is due to an “unforeseen workload.”

Damon Lew, UCSF’s assistant director of community relations, says master arborist Kent Julin is helping the university draft a new EIR, tentatively slated for release this fall, that will address all 300 comments. Julin says he can’t discuss the new report’s progress, but says that the state of Sutro Forest is grim. Invasive species like blackberry and English ivy are overwhelming the ecosystem and choking the previous inhabitants—and, more importantly, creating a severe fire hazard by collecting “fine fuel” like twigs and leaves. Typically, in a forest like this, a disturbance of some sort—like a fire—would clear the thick understory and allow new trees to grow. But fire isn’t an acceptable management option in a densely populated city where local firefighters have more experience with burning buildings than  forest fires,

But some now argue that never mind an intentional, controlled burn: the entire area could go up in an uncontrolled blaze. Longtime San Francisco city gardener, native plant advocate, and Sutro Steward volunteer Jake Sigg sees fire as a distinct possibility in the city’s drought-stressed, sick eucalyptus groves.

“People find it hard to credit the possibility of a fire in these areas,” Sigg wrote in his Nature News email newsletter on June 10. But he describes stumbling into a chest-high pit of dry fuel five years ago and having an “epiphany” about the alarming level of fuel accumulation in the forest. “The long strips of annually-shedding blue gum bark have been known to carry fire 12 miles, enough to carry glowing embers from San Francisco to the East Bay hills,” he wrote. “At the risk of sounding alarmist, it is not unrealistic to portray a scenario of a rare General Alarm fire.”

Julin says he agrees, especially given this year’s drought. “On any given day in the summertime, if there’s no fog, there’s a potential for a fire.”

Although UCSF does basic fire prevention maintenance—last summer, workers cleared vegetation away from the roads through the grove and this year cut back growth from campus housing and other UCSF structures— Dawson and Julin say they worry it’s not enough. “The issue that we have been talking about for 16 years has suddenly come to a boil,” Dawson said. “There’s no question these trees are sick, there’s no question whether these trees are going to survive—they are not—and this [current state of the forest] is a game changer.”

As he walks through the forest Dawson gestures at thick ivy and blackberry vines that  snake their way up pale tree trunks. Among other impacts, the brambly mess makes it difficult for birds of prey, such as the great horned owl, to hunt rodents, forcing the birds to  the forest’s outer edges. A dead tree catches Dawson’s eye. The trunk, barely visible through the thick green net of ivy, is huge, but as it stretches into the sky, the branches are smaller and bare. The only green is the emerald of the ivy, and the only sign of the former canopy is the skeletal remains of dead eucalyptus.

“Look at that, that’s all ivy, the tree is being supported just by ivy,” Dawson says.

The problems have become so great, the tangle in the forest so dense, that there is no easy solution. Bulldozers can temporarily clear away blackberry and ivy, but that also spreads  the seeds, ensuring the invasive plants will come back just as strong. Eucalyptus themselves are notoriously difficult to remove: cut the trunk off and they will resprout if not treated. Bag the trunk to prevent regrowth and the tree can resprout in multiple places, all along its roots. Poison the tree and it will suck up the poison and send it out into its roots, killing everything around it. To remove a single tree can cost thousands of dollars; multiply that by the 45,000 (or so) trees in the reserve.

Back at the foot of the three-headed tree, the cyclists decide to take a trail that veers off in the opposite direction of the unnatural phenomenon. They zip off through the trees, calling back and forth to each other. A few joggers also pass by, earbuds in, enjoying the breeze filtering through the forest. Dawson and I pick our way back through the dense understory, listening carefully for the slightest hint of a cracking branch.