Native Plant of the Month: Redwood Sorrel
Redwood sorrel is native to the Pacific Northwest forests from Southern British Columbia down through California. It is in the Oxalidaceae (or wood sorrel) family, named for the high concentrations of oxalic acid that these plants have in their tissues which give them a sour taste. Redwood sorrel has been eaten as a tangy green with dried fish and other dishes and used medicinally by Indigenous peoples throughout the Pacific Northwest. It is also in the same genus as sourgrass or Bermuda grass (Oxalis pes-caprae), a common invasive species with distinctive yellow flowers and notable for its sour flavor. Because of the oxalic acid concentrations, these plants should not be eaten raw in large quantities.
Redwood sorrel is characterized by having 3 leaflets that are waxy and light to dark green. Unlike true clovers that are in the pea family, the sorrels have heart-shaped leaflets. The underside of the leaflets have a silvery purple color. The flowers are white to pink with 5 petals and sepals. This plant only grows about 5-15 cm tall but can spread quickly via rhizomes.
Redwood sorrel is adapted to photosynthesize in low light environments, under the shade of trees. The leaves are heliotropic and follow the sun! However, if exposed to intense sunlight, the delicate leaves will fold in half.
Growing Redwood Sorrel at Home
As indicated by its name, redwood sorrel does well in redwood or Douglas fir forests near woodland creeks and streams. This plant can be used as a ground cover in your garden as long as your space is shady and moist. Plant them in a very shady place alongside other understory species, such as woodland strawberry (Fragaria vesca), yerba buena (Clinopodium douglasii), hairy honeysuckle (Lonicera hispidula), alumroot (Heuchera micrantha), and Douglas iris (Iris douglasiana), and snowberry (Symphoricarpos spp.).
Where to Find Redwood Sorrel
Redwood sorrel can be found closeby at Grassroots Ecology’s restoration project at Redwood Grove Nature Preserve in Los Altos and El Palo Alto Park in Palo Alto, as well as in the redwood and Douglas fir forests of the Santa Cruz Mountains, Marin Headlands, and Muir Woods. Our nursery grows native plants including redwood sorrel using cuttings carefully and sustainably sourced from local watersheds. Check out our latest inventory for online sales here:
We will also be selling plants on Saturday, October 19th, 2024 at the California Native Plant Society (CNPS) Fall Plant Sale, held at Hidden Villa in Los Altos Hills.
References
By Laura Powers, Watershed Stewards Program Corpsmember Alumni
