This native annual plant is ½3' tall, branching sparingly. The central stem is glabrous and occasionally angular. The opposite leaves are up to 5" long and 1" across, although usually smaller in size. They are linear-oblong to lanceolate-ovate, serrated along the margins, and hairless. These leaves are never lobed nor pinnately compound. At the base, the pairs of opposite leaves clasp the stem and nearly surround it (i.e., they're connate), or they are sessile. The upper stems terminate in flowerheads about ½1½" across. These flowerheads have a tendency to nod downward with age and the central head of disk florets becomes larger and more rounded. Each disk floret is yellow with 5 tiny lobes. There are about 8 ray florets surrounding the disk florets, but sometimes the flowerheads are without ray florets. The ray florets are variable in length, depending on the local ecotype. At the base of each flowerhead, there are both inner and outer bracts. The inner bracts are pale yellow, membranous along the margins, and rather broad, tapering to blunt tips. The outer bracts are green and oblong-linear. These latter bracts are about as long or longer than the ray florets, but they have a tendency to curl backward with age. There are about 6 outer bracts per flowerhead. The blooming period occurs from late summer to early fall and lasts about 1-2 months for a colony of plants. Each achene is oblong, although broader and somewhat truncated at its apex, where there are usually 4 barbed awns. The root system is shallow and branches frequently. This plant often forms colonies and spreads by reseeding itself; sometimes the lower portion of a stem will form rootlets at the leaf nodes when it lies against moist soil. Nodding Bur-Marigold is rather variable across its range.