Golden Gate Makes Its First Outplanting of Endangered Hickman’s Potentilla

The Golden Gate National Parks Conservancy's Marin Headlands Native Plant Nursery raised 56 Hickman's potentilla seedlings for planting at Rancho Corral de Tierra, spread across weeded and unweeded plots in six microhabitats. NPS / Eric Wrubel.

In early January 2022, staff at Golden Gate National Recreation Area took a new step to save the endangered Hickman's potentilla (Potentilla hickmanii): for the first time, they planted it out at Rancho Corral de Tierra.

A plant with almost nowhere left

• Hickman's potentilla is a federally endangered herb in the rose family, with yellow flowers whose petals are shaped like hearts.
• About 99% of all known plants grow at Rancho, in San Mateo County, especially on the grassy ridges at the foot of Montara Mountain.
• The only other surviving population is in Monterey County, with fewer than 80 plants.
• After decades of decline driven mostly by coastal development, the biggest threats now are invasive species and climate change.

To give the species a better future, botanists have started a set of new conservation projects.

Step one: a seed bank

Golden Gate is working with the University of California Botanical Garden to build a seed bank for the Rancho population.

• Staff collected seeds in 2020 and 2021 from more than 80 maternal lines, to keep genetic diversity.
• The goal is to collect and store 3,000 seeds in all, which will probably take several more years.

Step two: the first outplanting

The planting grew out of that seed bank.

• The Golden Gate National Parks Conservancy's Marin Headlands Native Plant Nursery raised 56 plants from the collected seed. The seeds germinated very well and the plants thrived in the nursery.
• In January the seedlings went into suitable habitat at Rancho.
• Because the effort is so new, it's an experiment: the plants are spread across weeded and unweeded plots in six microhabitats.

Over the coming months and years the plants will be tended and monitored closely, to work out best practices for future plantings. Learning which outplanting methods work is key to improving recovery strategies — and an important step toward more, larger and more resilient populations of Hickman's potentilla.

Sources

Based on "In Conservation Milestone, Staff Complete First Outplanting of Endangered Hickman's Potentilla in Golden Gate," Bay Area Nature & Science Blog, National Park Service, February 2022; a work of the United States government in the public domain.