Pink Evening Primrose
Originally native only to central grasslands from Missouri and Nebraska south through Kansas, Oklahoma, and Texas to northeastern Mexico, Pink ladies or Pink evening primrose is an upright to sprawling, 1 1/2 ft. perennial, which spreads to form extensive colonies. Its large, four-petaled flowers, solitary from leaf axils, range in color from dark pink to white. Nodding buds, opening into pink or white flowers, are in the upper leaf axils on slender, downy stems. The delicate-textured, cup-shaped blossoms are lined with pink or red veins. Foliage is usually linear and pinnate, although leaves can be entire and lance-shaped depending on locality. A hardy and drought resistant species that can form colonies of considerable size. The flowers may be as small as 1" (2.5 cm) wide under drought conditions. The plant is frequently grown in gardens and escapes from cultivation.
As the common name implies, most evening primrose species open their flowers in the evening, closing them again early each morning. The flowers of some members of the genus open in the evening so rapidly that the movement can almost be observed. Pink evening primrose populations in the southern part of its natural range, however, open their flowers in the morning and close them each evening. To further complicate matters, populations in the northern parts of its range tend to open in the evening.