High Plains Gardening
The gardening website of the Texas High Plains Region
Showy evening primrose is a plains states native, including the Texas Panhandle. Showy evening primrose blooms whitish pink in late spring, with each flower lasting a single day, opening in the morning and closing later in the day. The leaves are green narrow and lance-like and emerge from spreading rhizomes. The plant spreads prolifically by rhizomes and seeds, especially in amended and well watered soil. It is not well mannered in a mixed bed or border, I consider it invasive for the garden.
It will take over an amended bed or border with medium watering, but it can be useful in sandy soils when given enough room and neglect.
Watch for signs of spreading outside its location.