Rosettes of oblong leaves with pointed tips subtend tufted evening-primrose's flower stalks. Each large, white flower has four, heart-shaped petals and eight yellow stamens. The flowers open in late afternoon, close the next morning, and wither to pink or red-violet. Lateral roots may give rise to new perennial plants. Height: 4-6 in (10-15 cm).
Dry buttes, exposed hillsides, and open woods.
Washington to western North Dakota, south to southern California and New Mexico.