Calochortus invenustus is a species of flowering plant in the lily family known by the common name plain mariposa lily. It is native to the mountain ranges of California, where it grows in the coniferous forests. Its range may extend just into Nevada. It is a perennial herb which produces a slender, mostly unbranched stem up to 50 centimeters tall. There is a basal leaf 10 to 20 centimeters long which withers at flowering. The flower cluster bears 1 to 6 erect bell-shaped flowers in a loose cluster. Each flower has three sepals and three petals which are usually white to light purple and may have spotting low at the base and greenish streaking on the outer surfaces. The fruit is an angled capsule up to 7 centimeters long.