Scientific Name: Holocarpha macradenia
Status: T, CH
Santa Cruz Tarplant is a spreading, aromatic and glandular annual herb in the sunflower family with yellow flowers in dense heads. It occurs in clay soils in grasslands and competes poorly with introduced annual grasses. This tarplant was once found in most San Francisco Bay Area counties and south to Monterey County. Development has resulted in the extirpation of all natural populations in the counties surrounding the Bay. The last of these was destroyed in 1993. The species is now limited to less than 15 natural populations in Santa Cruz and Monterey counties; the largest population of Santa Cruz Tarplant occurs at the Watsonville Airport, which is attempting to establish new sites and enhance existing sites in this region.
Threats: Continued urban development, conversion to agriculture, competition from non-native plants, and ecologically inappropriate habitat disturbance (cattle, mowing, and discing), which facilitates the spread and growth of alien plants.