Calochortus nuttallii — known as sego lily — is a bulbous perennial which is endemic to the Western United States.

It is the state flower of Utah. Calochortus nuttallii are around 15–45 cm (6–18 inches) in height and have linear leaves.[3]

Plants have 1 to 4 flowers, each with 3 white petals (and 3 sepals) which are tinged with lilac (occasionally magenta) and have a purplish band radiating from the yellow base. A yellow petaled form with deep purple bands is known from Petrified Forest National Park.[4] The plant blooms in early summer, with flowers that can be up to 3 inches across.