This native biennial plant forms a rosette of leaves during the 1st year. During the 2nd year, it becomes a rather lanky plant about 2-4' tall that branches occasionally. The stems have abundant white hairs; the lower central stem is often ribbed. The basal and lower leaves are up to 6" long and 3½" across; they are cordate-ovate or ovate with petioles up to 2" long. The upper leaves are narrowly ovate and sessile, otherwise they are similar to the lower leaves. The dark green surface of each leaf has short fine hairs along the major veins. Both the lower and upper leaves alternate along the stems. The upper stems terminate in flowering racemes about 4-12" long; sometimes non-terminal racemes or individual flowers develop from the axils of the upper leaves. The stalks of these racemes are pubescent, and small leafy bracts may develop underneath some of the flowers. Each flower is about 1/8" across, consisting of 5 petals and a hairy green calyx with 5 long teeth. The petals are white and well-rounded; less often, they are light blue. The blooming period occurs during the summer and lasts about 2-3 months; only a few flowers are in bloom at the same time and they are fairly inconspicuous. Each flower is replaced by a prickly globoid fruit that hangs downward from a short slender pedicel. Prickles densely cover the surface of this fruit. Each fruit is initially whitish green, but later becomes brown; it contains 4 nutlets. The root system consists of a taproot. This plant spreads by reseeding itself; it occasionally forms colonies.