Tough tarweeds

California’s summer flower

With summer heat descending on the woodlands and prairies of Solano county, the brilliant springtime hues of lupines, goldfields, and poppies have been replaced by the unbroken gold of drying grass. In this time of long days and intense heat, have no fear! You can still find a group of true California natives: the beautiful, unique, and unfortunately named, tarweeds.

Thanks to donor-funded stewardship and sustainable rangeland grazing practices, native tarweeds thrive on Solano Land Trust properties. At Lynch Canyon, the white-flowered hayfield tarweed is found throughout the grasslands alongside trails. Another species, the pappose tarweed, commonly occurs along the Spring Branch Cutoff trail at Rush Ranch.  At Rockville Trails Preserve, the slender tarweed and common tarweed continues to put forth its yellow blooms.

Common tarweed can be found at Rockville Trails Preserve.

Look for hayfield tarweed at Lynch Canyon.

Last, but not least, is the pappose tarweed at Rush Ranch.

California harbors at least 30 plants called tarweeds. These diverse plants that have adapted to nearly every corner of California share some common features. As members of the Aster family, all of them have complex blooms made up of disk flowers and ray flowers like sunflowers and daisies, which belong to the same family. Many species secrete a strong smelling, sticky sap-like substance from tiny hairs – the origin of the common name “tarweed.” Their odor and spiny leaves have evolved to help them escape hungry plant eaters, like cattle.

Tarweeds are well-adapted to our Mediterranean summers, first emerging in late spring and often blooming at length through the hottest part of the year. At the end of the dry season, the plant drops its seeds and dies, with the tiny seeds lying dormant throughout the winter.

The next time you visit one of our properties, keep a lookout for these hearty California natives, which blossom in landscapes you help preserve.

Text by stewardship coordinator Ryan Lewis and photos by Doug Wirtz.