This climbing non-woody vine is a native perennial up to 8' long that branches occasionally. The light green to purple stems are terete, slightly speckled, glabrous, and often glaucous. Alternate leaves up to 3½" long and 2½" across occur at intervals along each stem; they are ovate-oval to broadly ovate-lanceolate in shape, smooth along their margins, and parallel-veined. The upper surfaces of the leaves are medium green and glabrous, while their lower surfaces are pale green and hairless. There are no hairs along the raised veins on the leaf undersides. The petioles of the leaves are up to 1¾" long, light green, and hairless. At the base of most petioles, there is a pair of tendrils that can cling to adjacent vegetation or objects for support. At the base of each stem on the vine, there is an appressed to slightly spreading sheath that is usually bladeless. Individual umbels of flowers are produced from the axils of the middle to upper leaves of each mature vine. Each umbel is connected to the stem by a long stout peduncle about 4-10" long. The peduncles are 4-8 times longer than the petioles of adjacent leaves; they are similar in appearance to the stems. Individual umbels are about 1½3" across, consisting of 20-120 flowers on slender pedicels; when fully developed, they are globoid in shape. Like other species in this genus, Smooth Carrion Flower is dioecious; some vines produce only staminate (male) flowers, while other vines produce only pistillate (female) flowers. The green to yellowish green staminate flowers are individually about ¼" across, consisting of 6 lanceolate tepals and 6 stamens with white anthers. The green to yellowish green pistillate flowers are individually about ¼" across, consisting of 6 lanceolate tepals and a pistil with 3 flattened stigmata. The tepals of both kinds of flowers are often recurved. The blooming period occurs from late spring to early summer and lasts about 3 weeks. The flowers often have a carrion-like scent, but its presence and strength varies with the local ecotype. Staminate flowers wither away after blooming, while pistillate flowers are replaced by globoid fleshy berries. Individual berries are about ¼" across and contain about 3-5 seeds; they are dark blue and glaucous at maturity. At the end of the growing season, the entire vine dies down to the ground.