The last, wild Franciscan Manzanita was believed to have perished in the 1940s when the city cemeteries where it grew were moved south to allow for neighborhood expansion.
But when construction crews recently cleared eucalyptus trees in the city's Presidio area, it exposed the only specimen known to exist in the wild.
Botanist Daniel Gluesenkamp spotted the manzanita shrub in the Presidio, a federal park overseen by the National Park Service.
Gluesenkamp reportedly spotted the rare shrub, which he was familiar with through his scientific work, as he drove from the Golden Gate Bridge into the Presidio. He later visited the site to confirm his sighting — the first in nearly 70 years.