An Inconvenient Plant

And while people killing trees can induce general fury, trees killing native plants doesn't seem to bother most folks. "What you're doing when you plant those trees is trapping the fog, which condenses on the leaves and needles and drops as artificial rain, increasing the precipitation by a third," says Steve Edwards, the director of the Regional Parks Botanic Garden in Berkeley's Tilden Park. "You foster a jungle of blackberries, ivy, and poison oak."

A strikingly tall and thin man with a long white beard of the sort fashionable in the time of President Rutherford B. Hayes (whom he resembles more than a little), Edwards refers to the nonnative trees shading the Raven's manzanita and other native species as "junk plants."

"The main things those trees do is reduce the native diversity," he says. "There would have been, like, 60 types of native plants growing there, maybe 100. And a lot of them are very rare and unique to the site. When you plant those trees, you end up with maybe two or three species. You reduce the uniqueness of California to a homogenized redundancy."

Statistics back up Edwards' scenario: Fully half of the native San Francisco vegetation listed in the 1958 edition of John Thomas Howell, Peter Raven, and Peter Rubtzoff's A Flora of San Francisco, California has been driven to extinction. When asked whether it's worth clearing out 75 acres of trees to benefit native plants, Edwards seems insulted: "We're talking about a postage stamp of land. It's the least we can do."

He shakes his head. "The whole of San Francisco was once a floral treasure trove. Can't we do just a little bit? My God!"

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.