Holocarpha obconica

Holocarpha obconica, commonly known as the San Joaquin tarweed, is a North American plant species in the sunflower family. It is endemic to (found only in) California, primarily in the Central Valley and adjacent regions.

The epithet "obconica" means "obconical," in other words, shaped like a cone but with the widest part farthest from the base. Achenes of H. obconica are obconical. The plant is a resin-containing herb up to 120 cm (4 feet) tall. It produces numerous flower heads, each head containing 4–9 yellow ray flowers surrounding 11–21 small yellow disc flowers, the disc flowers having yellow or brown anthers.