Sunday, October 10, 2010
On a cold and foggy late-summer Saturday, Recreation and Park Department gardeners, volunteers and neighborhood residents turned out to help reclaim part of Laurel Hill Park for San Francisco’s native plants. The park’s baseball field was once part of Laurel Hill Cemetery, the historic last refuge for the endangered Franciscan manzanita. Thanks to neighbor Rose Hillson’s vision and persistence, manzanitas and other natives may be returning to the slopes above the field.
Hillson learned about the city’s unique botanical heritage when she and her husband, Steve, bought a house on the site of the former cemetery caretaker’s residence. Clearing away the overgrowth in their yard, they discovered a struggling manzanita that didn’t match anything in the reference books or local botanical gardens.
Hillson connected with Tom Parker and Mike Vasey at San Francisco State University, who are still investigating the mystery manzanita’s genetics. In the meantime, she successfully campaigned for landmark status for the plant.
Her interest in Laurel Hill began with the death of a blue-blossom ceanothus bush. "It was the grandmother ceanothus, the biggest one here," she said. "I came by one day and thought, ‘Something is missing here.’ " Rec and Park Volunteer Services Director Kristin Bowman said she doesn’t know why it was cut down: "It’s a mystery."
Other gnarly old ceanothuses survived, though, probably part of the original landscape. Hillson learned more about that landscape from San Francisco State graduate student Michael Chasse.
"The baseball field is actually the quarry from Laurel Hill Cemetery," she explained.
One of the city’s Big Four cemeteries, it was founded in 1854 as Lone Mountain Cemetery. After the 1906 quake and fire, unclaimed bodies were buried there. "Most of the dead were moved to Colma in the 1930s," Hillson said, "but there are still some discoveries now and then. Homeowners find finger bones and tombstones with inscriptions."
There were no graves in the quarry area, however, which was a source of serpentine rock to line the cemetery’s paths.
Hillson and Chasse found old maps of the quarry at the Society of California Pioneers library. Chasse also found manzanita specimens from the cemetery at the California Academy of Sciences herbarium, and concluded that both Franciscan manzanita and Raven’s manzanita grew there.
Sole surviving Raven
The only surviving wild Raven’s is a single plant in the Presidio. The Franciscan species was believed extinct in the wild until last year, when a lone holdout was discovered, also in the Presidio, in the path of the Doyle Drive expansion. The plant was moved to an undisclosed location.
According to Chasse, San Francisco must have been a hot spot of manzanita diversity.
"There are some widespread manzanitas and some really localized ones," he said. "Lake Merced has a unique sand dune manzanita."
Genetic tests of the Presidio’s Franciscan manzanita found evidence that an ancestor had hybridized with yet another species, bearberry, which has never been documented in the city.
Laurel Hill’s original manzanitas and ceanothus would have shared the quarry slopes with coast live oak, toyon, huckleberry and buckwheat, the species Hillson hopes to restore.
"The goal is to get rid of all the weeds and nonnative growth, and clear the area for native plants with a San Francisco genotype," she said. "Steve Elder has people at the Parks and Recreation nursery who are growing blue-blossom for planting here." She envisions offspring of the manzanita in her yard as part of the mix.
The project is still in its early stages, with a daunting amount of agapanthus to be removed. "This is rigorous work," said Bowman. On the recent summer workday, volunteers from Onebrick, a nonprofit that connects willing hands with Bay Area events, provided the muscle, along with the Hillsons and three Rec and Park gardeners. Work days start at 9 a.m. on the third Saturday of alternate months. The next is Oct. 16 (401 Euclid Ave., at Collins).
‘Field of dreams’
"Rec and Park provides tools, guidance, safety overview and refreshments," Brown said.
For gardener Kuo Yee, Laurel Hill is home turf: "I played baseball here. I try to keep this a little field of dreams."
The weeding crew lobbed a constant, amusing volley of lost balls onto the field.
"We have opportunities in places like Laurel Hill to have historical botanical preservation of the species that grew here," Chasse said. "Protecting San Francisco’s natural heritage is a work in progress. This is another chapter."
News Source: San Francisco Chronicle
More info: www.sfgate.com…