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Higher Education

Why I’m trying to learn the name of every tree species in San Francisco.

Editor’s Note: This is one of many stories about our relationship with the natural world, which San Francisco is publishing over the next month as part of the May 2017 Great Outdoors Issue. To read stories as they become available online, click here.

Sometime in the
second half of 2016, I set out on a series of neighborhood walks with my friend Masha—like me, a fan of four-hour urban investigations, but, unlike me, possessed of a deep store of botanical knowledge. On these walks I learned the name of the jacaranda, the tree, it turned out, whose lavender blossoms had floated down over the proceedings at my best friend’s wedding a decade earlier. I saw my first Norfolk Island pine, outlandishly sculpted by evolution to resemble some crowning achievement of mid-century modern design. I found out that running one’s hand along the trunk of a flaxleaf paperbark tree is indeed like petting a stack of handmade looseleaf. And I became acquainted with the ginkgo, contemporary of dinosaurs, the female seldom seen here owing to the puke-like tang of its fruit.

It felt strange to suddenly know these things, given that trees had previously presented as an agreeable peripheral blur while I wandered through the city that’s been my home for 23 years. It wasn’t that I didn’t care about nature, but I’d always been a pretty vague, generalist appreciator, whether walking out to the end of Tomales Point in Marin or traversing the hillside gardens flanking the staircases above the Castro. So it’s unclear why 2016—an exciting time in all our lives—was the year I precipitously turned into someone who spends her weekends peering up at shaggy bark, catkins, and pinnately compound leaf arrangements, murmuring names like “shoestring acacia” and “mountain she-oak.”

Some share of the credit—or blame—resides with a man named Mike Sullivan, to whom Masha and I had developed a somewhat cult follower–like attachment. Onetime board president of Friends of the Urban Forest and keeper of the blog San Francisco Trees, Sullivan wrote the essential urban-forest guidebook The Trees of San Francisco, a compendium of walking tours and tree profiles that has taken us in search of European hornbeams in Potrero Hill, Port Orford cedars in the Panhandle, and Sydney golden wattles in Pacific Heights—where I also caught my first glimpse of the controversial Monterey cypress hedge enshrouding the Spreckels mansion, home to romance novelist Danielle Steel.

By the time we’d finished our debut tour and I’d seen my first gorgeous, willowy mayten and crushed between my fingers the deliciously fragrant leaves of my first California pepper, I found it baffling that I could have been so unconcerned with the names, morphology, and customs of an entire charismatic category of this planet’s living things. I resolved to get on a first-name basis with as many San Francisco representatives—124,795 street trees, encompassing some 500 species, per a city census completed in January—as I could find. 

It sounds a bit compulsive, like some kind of taxonomic hoarding. But I think there’s more to it than just a drive to collect facts. When I met up with Sullivan in March, he pointed out that learning to identify San Francisco’s urban forest can also be an extension of the glorious perennial occupation of learning to know San Francisco itself. We were walking through Parnassus Heights, where Sullivan, a startup and venture capital lawyer by trade, lives with his husband, their son, and a dog named Mather (after the city-owned family camp in Yosemite). As we paused on Parnassus Avenue opposite a row of red flowering gums, one of many antipodean species that love our foggy coastal climate, he talked about the “serendipitous” discoveries he’s made, arboreal and otherwise, walking around the city during his 33-year tenure here.

And these tree walks do feel like an outgrowth of two-plus decades of urban explorations that have rewarded me with a more densely annotated map of this city I adore. In the new year, waiting for the Bailey’s acacias to bloom, and then the Victorian boxes, and then the California buckeyes, it dawned on me that, contrary to conventional wisdom, San Francisco has seasons, erratic and overlapping though they may be. Even the fallen leaves of a towering silk oak that pile up outside the doorway of the hipster barbershop down the block from my house have somehow come to texture my understanding of this place. 

That richness has activated something, too, a renewed ability to be curious and dazzled in a city where I’ve lately been more focused on a distressing housing market, on anxieties about how much longer, as a renter, I’ll be able to hang on here. Spending time staring up at the aerial root systems of New Zealand Christmas trees, or crumpling and smelling a bay laurel leaf like the ones I put in my stockpot, or learning to pick out the metallic sound of the Anna’s hummingbirds that frequent the bottlebrushes, I suppose I’m doubling down on my emotional stake in San Francisco, amid uncertainty, despite possible heartbreak ahead. Maybe there’s something consoling about keeping company with the city’s most permanent residents.

As Sullivan pointed out, many of them, far from their native soil, reflect the contradictory emergence, over the years, of a treescape unique to San Francisco, one that self-selects for thriving amid sandy soils, harsh winds, fog, seven or eight months without rain, and, of course, cement. Noting that he could be dropped into a San Francisco stripped bare of any other identifying markers and know it by its trees, Sullivan said, “We’ve almost created our own native urban forest here.” It was a remark unlikely to thrill the local purists who dream of ridding the city of invasive plants—a ship that has long since sailed out of San Francisco Bay. But I found the idea evocative, and after we’d said our goodbyes and I was walking home over the 17th Street hill, I realized that my map of the city, with its singular population of trees, had gained another new overlay.

Wandering through Parnassus Heights a few weeks later on our own, Masha and I passed the 20-foot-tall soapbark tree that Sullivan and his husband had planted on the sidewalk outside their house the week in 2004 that their son was born. I was happy they’d been able to put down roots, and envious, too, because I hadn’t managed to do the same in this wondrous place with its inhospitable soil. That ship, too, had probably sailed. Or maybe it hadn’t. We continued walking through the urban forest, searching for unknown points on a map, eyes turned upward toward the branches.


Originally published in the May issue of San Francisco

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