As part of our mission to steward the biodiversity of Sonoma Valley, Sonoma Ecology Center, along with partners from California Department of Fish & Wildlife (CDFW), U.S. Fish and Wildlife Service (USFWS), and UC Berkeley Botanical Garden conducted a site visit this past September to collect seeds of the endangered Kenwood Marsh Checkerbloom (commonly known as the Checkermallow), or Sidalcea oregana ssp. valida. This effort is part of our long-term commitment to save this endemic and eye-catching wildflower. 

SEC has been working in concert with CDFW and the landowner of Deerfield Ranch Winery to whom it is owed special thanks for their partnership in helping this species survive for multiple seasons – with propagation efforts occurring at our native plant nursery at the Sonoma Garden Park and conservation efforts occurring seasonally in the field.

The endangered Kenwood Marsh Checkerbloom can grow from three to four feet tall with deep pink blooms that show up from late June to September. This picture was taken by Raffica La Rosa, Senior Environmental Scientist at the California Department of Fish and Wildlife (CDFW) at the seed collection event.

Currently, there are only two known populations of this species left in the world. One population is in Kenwood, and one is in Knights Valley, both in Sonoma County. To save the Checkerbloom from going extinct, we have spearheaded a number of projects to protect these special flowers in close collaboration with partners. The California Department of Fish and Wildlife identifies the greatest threat to the Kenwood Marsh Checkerbloom as “altered hydrology resulting from the diversion of water from a Sonoma Creek tributary stream for agricultural purposes.” Sonoma Ecology Center actively addresses this issue through outreach with local landowners and by offering alternatives such as rainwater catchment systems. Some of the initiatives we have participated in to protect this species include removing non-native plants from the area, propagation of the plant at our Native Plant Nursery, and working to conserve seeds. 

Raffica LaRosa from CDFW (left) and Steven Lee (right) collecting seeds at the Deerfield Ranch Winery property in September.

This summer, Steven Lee, our Senior Scientist and Research Program Manager stopped by the Kenwood Marsh Checkerbloom’s location to check on their status. After seeing that the plants were doing very well and started to set seeds, he communicated with our partners and put together a seed collection event, even though we did not have specific grant funding for this project. Five representatives of different organizations collected the Checkerbloom seeds for conservation and potential recovery activities. In total, Steven Lee and Hannah Aclufi from Sonoma Ecology Center were joined by Raffica La Rosa from CDFW, Stephen Curry from USFWS, and Holly Forbes and Sophia Warsh from UC Berkeley Botanical Garden to collect and conserve seeds of this endangered species.

From left to right: Steven Lee, SEC’s Senior Scientist and Research Program Manager, Hannah Aclufi, SEC’s Native Plant Nursery Manager, Sophia Warsh, Assistant Curator at UC Berkeley Botanical Garden, and Stephen Curry, Regional Recovery Permit Biologist at U.S. Fish and Wildlife Service.

Despite having previously propagated this species in our Native Plant Nursery, Nursery Manager Hannah Aclufi saw the Checkerbloom for the first time in person on this outing: “I was honored to have the opportunity to work with such a knowledgeable group of scientists. It was very satisfying to see this rare checkerbloom blooming in such profusion in its natural habitat,” Hannah says.

Without this seed collection effort, the Checkerbloom seeds would probably be eaten by birds; some would make their way to replenish the seed bank in the soil. To conserve this species, the team collected around 10% of the total seed count, while letting the rest remain in the field. The seeds were sent to UC Berkeley Botanical Garden for processing and preservation in cold storage.