[2][4][5] The stem of Coreopsis gigantea is a trunk up to 1 metre (3+1⁄2 feet) tall, and 4–10 centimetres (1+1⁄2–4 inches) in diameter.

[6][7] It is summer deciduous, leaving a sculptural bare trunk and branches during the dry season.

[7] The plant is found in California coastal sage and chaparral habitats, from 14–55 m (45–180 ft) in elevation.

[2][6] It is found in coastal dunes, chaparral hillsides, and exposed sea bluff habitats.

[6] It is distributed on the coasts of: Southern California and the Channel Islands; the Central Coast region; San Francisco Bay Area; and in Mexico on the northwestern Baja California Peninsula and Guadalupe Island.