This native annual plant is 1-3' tall, branching occasionally in the upper half. The stems are glabrous or have a few scattered white hairs; they are often red in bright sunlight, otherwise green. The compound leaves are oddly pinnate, consisting of 3-5 leaflets. Sometimes, there are a few simple leaves near the flowerheads. These leaves occur oppositely along the stems; some of the upper leaves may be alternate. The compound leaves have long petioles. The leaflets are up to 3" long and 1" across. They are lanceolate, coarsely serrated, and usually hairless, although their lower surface may be slightly pubescent. Their tips are rather long and pointed. Some of the upper stems terminate in a single flowerhead about ¾–1" across on a long stalk; there may be 1 or 2 smaller flowerheads lower on the stalk. The flowerheads consist of numerous disk florets that are golden yellow; the ray florets are absent or barely perceptible. There are 5-10 leaf-like outer bracts surrounding the flowerheads; usually they are 8 in number. These bracts are green, and slightly ciliate or hairy, especially near the base of the flowerhead. The blooming period is usually late summer or early fall, and lasts about a month. There is no noticeable floral scent. The achenes are nearly black and rather slender, but becoming slightly wider toward the awns. These awns are long and slender, with tiny barbs that point downward. The root system consists of a shallow taproot that branches frequently. During the fall, the leaves often turn dark red.