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An Inconvenient Plant 

One of the world's rarest plants grows in the Presidio. Plans are under way to save it — and ax thousands of trees in the process.

Wednesday, Apr 16 2008

Page 4 of 5

At Lobos Creek, restorationists did more than a little bit: Back in 1996, a dozen acres of trees, ballfields, and prime teenager hanging-out areas were bulldozed in favor of rolling dunes dotted with San Francisco lessingia, an endangered native grassy herb.

Karin Hu offers a wan smile as she traverses the gray boardwalk weaving throughout the restored dunes in the extreme southwest corner of the Presidio. For the City College professor, the experience of returning to her childhood haunt is disillusioning in the same way Gertrude Stein was less than enthralled with her old Oakland neighborhood.

At Lobos Creek, there is.there there. The boardwalk sends a clear message: You are here. Nature is there. Hu grew up tromping through these open fields, and believes it played a role in her decision to study animal behavior. If her childhood forays had been restricted to the boardwalk, would her interest have been piqued?

While native-plant advocates have praised the restored dunes as a living museum, Hu feels the description is all too apt: "Museumification" is a much-used pejorative among restoration critics. "This boardwalk has made this area an 'exhibit' — but it's not a good enough exhibit for people to come out and see," she says. "I see kids out here doing restoration work, and that's great. But are they coming back on their own?"

Indeed, on an utterly gorgeous Sunday during the noontime hour, only four or five other people wandered along the boardwalk — none of them children.

The future dunes — and fenced-off, isolated Raven's manzanita recovery sites — may also be accessible only by narrow boardwalks, if at all. This leaves Hu highly ambivalent.

She isn't alone. Her unlikely kindred spirit is Raven (the man, not the plant). "I had a lot of fun when I was a kid there, wandering around collecting and finding plants," he says. "Fencing or putting certain areas off-limits is quite all right, but it would be an utter tragedy if it was done on a wide scale and kids don't have contact with nature. Putting aside a bigger area and keeping people out of it is kind of problematic."

Raven laments that children are no longer allowed to gallivant about the city with nary a care, as he did in the 1940s and '50s. But he grew truly agitated at the notion of natural areas being taken away from them. City kids need to know that nature isn't something accessible only after three hours on a bus. It's all around them and they should revel in it. Besides, if Raven had stuck to the path as a 14-year-old, he would never have discovered his manzanita in the first place.

So, paradoxically enough, converting San Francisco to a more "natural" state may actually make nature less accessible for its residents — and since it will require a maniacal amount of scientific, political, and administrative effort, it certainly won't come about naturally.

After half a century of merely keeping the Raven's manzanita alive, its recovery strategy has shifted into reproduction. In recent years, researchers have uncorked the biggest breakthrough in the plant's history since Peter Raven discovered it on the bluff — at times, however, in spite of themselves.

In 1994, UC Berkeley officials lent the only copy of their detailed research history on the plant to an undergraduate — who promptly lost it. Fourteen years later, garden curator Forbes is still visibly perturbed. But she doesn't need papers to remind her that, in 1995, she led an effort to harvest seed fruits from Raven's manzanitas. She and others plied 4,500 of them with 32 different treatments, including smoke and even sulfuric acid, meant to break the seeds' nigh-impenetrable coating.

For all that travail, 12 plants were germinated. Some of Forbes' seedlings, tall and upright, were obviously the herbal equivalent of the milkman's kids. But others certainly looked like Raven's manzanita. Could all the scientists have been wrong to peg the plant an obligate outcrosser? Could the manzanita have self-pollinated?

In 2004, San Francisco State biology professor Tom Parker commenced genetic testing on the six surviving UC Berkeley seedlings. Parker and technician Craig Reading wrapped up lab work at SFSU's Conservation Genetics Laboratory only this month. And Parker has concluded that three or possibly four of the UC Berkeley plants are 100 percent Raven's manzanita. The population of genetic individuals has suddenly quadrupled (or quintupled).

"Twenty years ago, if you'd have asked me about a single individual of an outcrossing plant and what to do about it, I'd have said you're wasting your money, man," says Parker, a friendly, middle-aged man in no way related to Elvis' former manager of the same name. "The plant was at the literal edge of extinction, and now it has been moved away from that. There's a lot of satisfaction there, I think."

The Presidio has invited every last person who has ever worked on the mother manzanita plant to a June pow-wow to discuss what comes next. You would think Parker's revelations would have the scientists turning cartwheels. But you'd be wrong.

"We'll all get in this room and talk and we might be arguing if this is the best use of our time and resources," Swenerton says. "Can we bring this plant back to a level where it will do well on its own? I don't think so."

With one plant or five, the gene pool for the Raven's manzanita is barely moist. If extinction can come in a form as mundane as a caterpillar, how can the plant evolve to cope with global warming?

Parker sees things differently. "If the plant has selfed [self-pollinated], then it's never too late." At a recent PowerPoint demonstration, he walked the audience through his slicing and dicing of multiple gametes and alleles, illustrating his work with a branching chart resembling a thrice-worked-over NCAA bracket. Heads nodded as Parker predicted a future in which sexually reproducing Raven's manzanitas are once again nestled in San Francisco's rocky hills.

About The Author

Joe Eskenazi

Joe Eskenazi

Joe Eskenazi was born in San Francisco, raised in the Bay Area, and attended U.C. Berkeley. He never left. "Your humble narrator" was a staff writer and columnist for SF Weekly from 2007 to 2015. He resides in the Excelsior with his wife, 4.3 miles from his birthplace and 5,474 from hers.


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