From https://www.wildflower.org/plants/result.php?id_plant=VEEN:
A well-branched grayish-green plant, leaves alternate or opposite, toothed, nearly triangular. Yellow flower heads are up to 2 inches (5 cm) across and have 3-toothed rays. The silvery green leaves are triangular with toothed margins.
This plant is common on disturbed ground and sometimes colors acres or miles of roadside solid yellow.