Madia is a genus of annual or perennial aromatic herbs in the family Asteraceae (order Asterales), placed in the tribe Madieae. The genus comprises 11 accepted species, commonly known as tarweeds — a name that reflects the intense, resinous stickiness of the foliage and stems. Plants bear yellow ray and disc flowers and produce small, dark achenes (seeds) that are rich in oils.
The genus is native to western North America — primarily California, Oregon, Washington, Nevada, Idaho, Montana, and British Columbia — with a disjunct occurrence in southwestern South America, particularly southern Chile and Argentina. Species occupy a range of open, often dry habitats such as grasslands, roadsides, and mountain slopes.
Several genera have historically been included within Madia or split from it, among them Anisocarpus, Harmonia, Jensia, and Kyhosia. The most widely recognized species include Madia elegans (common madia), Madia sativa (coast tarweed), Madia glomerata (mountain tarweed), Madia gracilis (grassy tarweed), and Madia chilensis, native to central Chile.
Tarweeds have long held cultural importance for Indigenous peoples of the Pacific Coast, whose tribes — including the Miwok, Hupa, Cahuilla, Chumash, and Maidu — harvested the oily seeds as a staple ingredient in pinole. The seeds are also a significant food source for birds and small mammals, including doves, quail, finches, sparrows, chipmunks, and ground squirrels.
Etymology
The genus name Madia is derived from the native Chilean name "Madi," applied to Madia sativa, the coast tarweed. The common name "tarweed" refers to the intense, resinous stickiness characteristic of the foliage and stems of plants in this genus.
Distribution
Madia species are native to western North America — concentrated in California, Oregon, Washington, Nevada, Idaho, Montana, and British Columbia — with an additional native range in southwestern South America, including southern Chile and Argentina. Madia sativa has scattered naturalized populations in eastern Canada and the northeastern United States.
Ecology
The dark, oily achenes of tarweeds are an important food source for a wide variety of birds and small mammals, including mourning doves, quail, blackbirds, finches, Oregon juncos, California horned larks, western meadowlarks, American pipits, sparrows, towhees, chipmunks, ground squirrels, and mice. Cottontail rabbits and chipmunks also browse the plants directly. The seeds are noted as abundant and highly nutritious.
Cultural Uses
Tarweed seeds have been harvested for centuries by Indigenous peoples of the Pacific Coast as a key ingredient in pinole, a ground seed preparation used as a staple food. The seeds of Madia elegans subsp. densifolia were among the most valued by the Miwok people. The Hupa, Cahuilla, Diegueño, Chumash, Costanoan, Kawaiisu, and Maidu tribes of California all used Madia species in pinole.
Taxonomy Notes
Madia belongs to tribe Madieae within Asteraceae. Several genera previously treated within Madia have been segregated, including Anisocarpus, Harmonia, Jensia, and Kyhosia. Among reclassified species, Madia bolanderi is now Kyhosia bolanderi, Madia madioides is now Anisocarpus madioides, and several former Madia species have been moved to Harmonia and Jensia. The genus currently comprises 11 accepted species.
