Ethnobotany. A food for many Amerindian Peoples: the bulbs were eaten raw or roasted.

Description from the Oregon Department of Agricuture. Howell’s mariposa lily is a bulbous perennial, 2-4 dm tall, that bears a single large basal leaf (averaging 30 cm in length). These deep green, somewhat leathery basal leaves are distinctly parallel-veined with rows of hairs on the undersides that correspond to the veins. The broadly cup-shaped, showy flowers have three white to cream-colored petals 2.7-3 cm long, each with a lime green petal spot that is covered with dark purple hairs. The upper portions of the petals have few or no hairs. Each stem usually produces one or two (sometimes three) flowers, which develop into 2-cm-long capsules that remain erect until seeds are released. Plants begin to bloom in mid June and can continue into August under ideal conditions. In most populations, many more vegetative than reproductive plants occur, with only a relatively few mature individuals flowering each year. The number of plants flowering varies greatly among years and is dependent on seasonal conditions.