Hemizonia congesta ssp. congesta
Here is the classic botanical description: "Leaves silvery canescent, inflorescence campanulate, phyllary tips shorter than body, ray flower ligules yellow". When the foliage is gently brushed, these annuals give off a distinctive tar-like odor. The yellow flowers appear in early to late summer, often long after the last rains. There is a presumed relationship between the resin and the plant's drought resistance. The specifics of this relationship are unknown and could be an avenue of research for the enterprising graduate student.
DISTRIBUTION: Coastal grasslands (sometimes on serpentine) from the southern North Coast Ranges to the San Francisco Bay Area; < 300 m.