Stanleya pinnata, also known as Prince's Plume, is a species of flowering plant in the mustard family known by the common name desert princesplume. It is native to the western United States, where it occurs in many types of open habitat, including deserts, foothills, rocky cliffs, sagebrush, and prairie. It prefers alkali- and gypsum-rich soils. It is a perennial herb or shrub producing several erect stems reaching up to about 1.5 meters in maximum height. The stems are hairless, often waxy in texture, and have woody bases. The leaves have fleshy blades up to 15 centimeters long by 5 wide which are divided into several long, narrow lobes. The blades are borne on petioles. The top of the stem is occupied by a long inflorescence which is a dense raceme of many flowers. Each flower has narrow yellowish sepals which open to reveal four bright yellow petals each up to 2 centimeters long. The stamens protruding from the flower's center may approach 3 centimeters in length. The fruit is a curving, wormlike silique up to 8 centimeters long.