many-flowered thelypodium

Thelypodium milleflorum is a biennial herb producing many erect stems, often approaching two meters in height. The stems are hairless, sometimes hollow and inflated, and often waxy in texture. The basal leaves have oblong to lance-shaped blades with toothed edges, and sometimes divided into segments. The large inflorescence is a dense, spikelike raceme of mustardlike flowers with white petals. The fruit is a narrow, flat silique up to 8 to 10 centimeters long.