Lepidium nitidum is a species of flowering plant in the mustard family known by the common name shining pepperweed. It is native to western North America from Washington to Baja California, and it may be found elsewhere as an introduced species. It thrives in a number of habitat types. This is a mainly erect annual herb producing a slender stem up to about 40 centimeters tall. There are small leaves along the stem and larger ones at the base growing up to 10 centimeters long and divided into many narrow lobes. At the top of the stem appear tiny flowers with spoon-shaped white petals only about a millimeter long. The flowers give way to flattened, rounded to oval-shaped disclike fruits up to about half a centimeter long. Each green to pink shiny fruit is divided down the center into two chambers containing seeds.