This introduced biennial plant is 2-5' tall and little branched, except occasionally near the base during the second year. During the first year, this plant consists of a low-growing rosette of basal leaves up to 1' across. These basal leaves are narrowly ovate or oblanceolate and dark green. Their margins are smooth and vertically undulate, sometimes even crinkly-edged, while their upper surface is hairless and shiny. The hairless round stems of plants during the second year have fine longitudinal veins that are dark green. The alternate leaves are up to 5" long and ¾" across, becoming smaller as they ascend the stems. They are narrowly ovate or oblong-linear in shape and more or less sessile against the stems, otherwise their appearance is similar to the basal leaves. The stems terminate in spike-like racemes of yellowish green flowers about ½2' long. The flowers are densely distributed in all directions along the length of the racemes. Each flower is ¼" or less across, consisting of 4 white petals (usually), 3-4 green sepals, 12-25 stamens with large yellow anthers, and a green capsule in the middle with 3-4 divided valves. The upper petal is larger than the lower petals (when they are present) and it has 3-6 slender lobes, while the lower petals have 3 slender lobes. These lobes provide the petals with a frilly appearance. There is some variability in the structure of the flowers, even on the same plant. The blooming period occurs from late spring to early summer and lasts about 1-2 months. The 3 or 4 valves of the ripened seed capsule become pointed at the top and split apart, releasing small flattened seeds that are reddish brown and orbicular-reniform (kidney-shaped, but nearly round). The root system consists of a stout taproot. This plant spreads by reseeding itself. Sometimes it forms colonies.