Written by Vinusha Ramesh, SVHS student and Coastal Watershed Council Restoration Intern
Description
Madia sativa, commonly known as Coast Tarweed, is an annual herb found in grasslands and disturbed areas. It exhibits small, dense, sunflower-like yellow flower heads and is covered in small glandular hairs that make the plant very sticky. Native to California, Coast Tarweed’s range also extends along the North American coastline up to Alaska, and down to South America. Madia sativa is one of 127 different species of tarweed, which occur across North America but are most diverse in California and Hawaii. As an annual, this plant has a brief life cycle, but produces large amounts of seeds to support the next generation. Its size can vary widely depending on the habitat, from as small as 8 inches to as tall as 8 feet! The species has even been seen growing at a diminutive 2 inches tall.
Ecological Significance
As its common name suggests, Coast Tarweed exudes a “tar”-like resin that reduces water loss from the plant’s tissue during long and dry summers. Tarweed readily produces an abundance of seeds, making it a plentiful food and nutrient source for birds, rodents, and even humans. Because of its deep roots and small leaves, Coast Tarweed reaches water trapped deep within the soil to limit water loss during the heat of the day. This makes it well adapted to growing and thriving in dry environments long after the rains have fallen. This hardy plant had one of the highest rates of success during the Coastal Watershed Council’s first year of planting from seed in our habitat enhancement efforts at the San Lorenzo River.
Traditional Uses
Coast Tarweed seeds were originally used in pinole, which was a staple food of the Indigenous people of the Pacific Coast. In addition to its intense stickiness, Coast Tarweed is also oily and aromatic. This led the Miwok, Hupa, Cahuilla, Chumash, and multiple other tribes to use the Madia species in making the pinole dish. The Yokuts also utilized Madia sativa seeds to add flavoring to manzanita cider.
Current Medicinal Uses
Tarweed is utilized in current herbal medicinal practices as a treatment for bronchial asthma. The plant is believed to desensitize the nerve endings in the bronchial tree, which in turn slows the heart rate and leads to easier respiration. Furthermore, the dried leaves of Coast Tarweed are anti-inflammatory, and are used as a natural treatment for poison oak and poison ivy, rashes, burns, and eczema.
How to Grow Madia sativa at Home
Interested in blooming your own tarweed? Plant the tarweed seeds in a pot of soil and allow the seeds to sink into the mixture. To ensure that your tarweed thrives, provide full sun exposure and minimal watering to avoid any rotting of the roots. Now you have created your own little California native plant hotspot!
Love Coast Tarweed? Join CWC for a River Health Day!
Every second Saturday of the month, the Coastal Watershed Council leads River Health Days where volunteers help plant and care for a variety of native plant species to increase biodiversity and habitat complexity and support a healthy river ecosystem. Coast Tarweed (Madia sativa) is one beneficial plant you may spot growing along the river. Sign up for an event here to get involved!
Sources:
Natural Resources Conservation Service, United States Department of Agriculture. “Plant Guide: Coast Tarweed.” https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_masa.pdf Accessed June 30, 2024.
Native Foods Nursery. “Tarweed.” https://nativefoodsnursery.com/tarweed/ Accessed June 30, 2024.
California Native Plant Society Yerba Bunea Chapter. “The Tarweeds.” https://cnps-yerbabuena.org/the-tarweeds/ Accessed June 30, 2024.