Chlorogalum angustifolium is a species of flowering plant in the lily family known by the common name narrowleaf soap plant. It is native to the Sierra Nevada foothills and inner North Coast Ranges of California, and the mountains of southern Oregon, where it grows in heavy, rocky soils in woodland and on grassy hillsides. This is a perennial wildflower growing from a fibrous bulb a few centimeters wide. It has narrow basal leaves only a few millimeters wide. The flower cluster may be up to 70 centimeters long and is composed of several ephemeral flowers which open in the evening and close by the following morning. Each has six petals about a centimeter long which are white with yellow-green midveins. There are six stamens tipped with large yellow anthers. The fruit is a capsule 1 to 3 millimeters long. The Karuk of northern California used the soapy juice from the crushed bulbs of this plant as a detergent for washing clothes.