Late season bloomer: Common tarweed (Madia elegans)
Long before valley-bottom fields, grasslands and open areas in the Klamath-Siskiyou bioregion were covered in non-native and invasive star thistle (Centaurea solstitialis) or dyer’s woad (Isatis tinctoria), some were covered with the dainty, yellow, daisy-like flowers of the native common tarweed (Madia elegans). Tarweed is an annual wildflower in the sunflower family. In the Klamath-Siskiyou it occurs in grasslands and open forest, typically at mid to low elevation. It flowers in summer and early autumn, from northern Oregon through the California Floristic Province and Great Basin Province south to Baja California. The flowers curl up during the daytime, opening late in the day and remaining open until the middle of the next morning. (An explanation of why can be read in this SF Gate article.) The foliage exudes fragrant oil, and the plants are sticky, hence the common name tarweed. It is an often-overlooked native plant that deserves more respect and attention. The seeds of tarweed are eaten by many birds and small mammals, such as mourning doves, quail, blackbirds, finches, Oregon juncos, California horned larks, western meadowlarks, American pipits, sparrows, towhees, mice, ground squirrels and chipmunks. Being a late bloomer, tarweed is an important late nectar source for butterflies, bees and other beneficial insects. Once, while picking tarweed seed, I discovered that there was a particular green caterpillar found in abundance in the large tarweed patch. After research I learned that the owlet moth (Heliothodes diminutiva) uses tarweed as it’s host plant, eating the reproductive organs (i.e flowers) of the plant as it grows, sometimes sterilizing the plant entirely. Tarweed seeds were also historically used as food by the local indiginous people; documented use of tarweed is known for the Hupa, Takelma, and Shasta tribes. Examples of how tarweed seeds were historically used include:
- Seeds parched and pounded into flour.
- Seeds roasted with hot coals, pounded or rolled into flour.
- Pulverized seeds eaten as a dry meal.
- Seeds used to make pinoles, where seeds were roasted and eaten alone or mixed with manzanita berries, acorns and pine nuts.
- Ground tarweed seeds mixed with ground hazelnuts and camas.