This native perennial plant is 1½2' tall and unbranched. The central stem is light green and usually slightly pubescent, otherwise it is glabrous. The leaves are usually opposite and angle strongly upward from the stem, otherwise they are alternate. They are up to 5" long and 1¾" across, and are usually lanceolate with short petioles. Because this is a variable species, the leaves can assume other forms as well. A typical leaf has a prominent central vein and smooth margins that gently undulate up and down. It is often slightly pubescent, otherwise glabrous. A single umbel of flowers may appear from the axils of the upper pairs of leaves. A typical plant will have 1-3 umbels, with each umbel consisting of 15-30 flowers. Each umbel has a short stalk and hangs downward. Each flower is about 1/3" long, consisting of 5 upper hoods and 5 deflexed petals. The hoods are without horns, and the central reproductive column is very short or absent. Instead, there are masses of winged pollinia. The flowers are light green to green, becoming yellowish green or purplish green as they age. Their pedicels are about ½" long and hairy. The blooming period occurs during early summer and lasts about 3 weeks. If successful cross-pollination occurs, a flower will be replaced by a spindle-shaped follicle about 5" long and 1" across at its widest. The surface of a follicle is smooth, but usually slightly pubescent. This splits open along one side, and releases numerous seeds, each one with a large tuft of white hair. Seed distribution is by wind. The root system consists of a central taproot. This plant occurs as widely scattered individuals, and rarely forms colonies.