Lithospermum ruderale is a species of flowering plant in the borage family known by the common name western stoneseed or lemonweed. It is native to western Canada and the western United States, where it can be found in many types of habitat. A perennial herb growing from a taproot and woody caudex, it is covered with fine, more or less upright, hairs, especially on the stems. It produces a cluster of erect leafy stems 20 to 50 centimeters tall. The stems support lance-shaped leaves up to 8 centimeters long. Bunches of flowers with leaf-like bracts appear toward the top of the stem amongst the leaves. The corolla is light yellow, often slightly greenish, and about a centimeter long and wide. The style is short. The fruit consists of one or two, sometimes four, clustered glossy grey nutlets,