The radially symmetrical composite flower heads measure 5 cm. in width. They have a central disk of highly reduced, dark yellow disk flowers that is surrounded by six to eight yellow, broad and rounded, petal-like rays with sharply tapered tips. Flowers are arranged singularly atop the terminal shoot. Flower heads nod increasingly as they mature.
The seed-like fruit is small and has two to four barbed spines.
The leaves are thin and long, measuring 5-15 cm. in length. They are smooth and stalkless with a clasping base. Leaves are arranged in an opposite fashion along the length of the stem.
Nodding bur marigold grows best in swamps, along stream banks, and generally over any moist ground.
The specific epithet, cernua, is Latin for "nodding" an refers to the nodding flower heads. These flowers heads become increasingly nodded as they mature.
Nodding bur marigold seeds are a food source for ducks and other water fowl.